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For other uses, see Ball (Disambiguation)

One of the most unique and integral items of the Metroid games, the Morph Ball (モーフボール Mōfu Bōru?), also previously known as the Morphing Ball (モーフィングボール Mōfingu Bōru?), Maru Mari (丸まり Marumari?) or Round Ball[1] is the Alt-Form of Samus Aran. It turns her into a sphere 0.8 meters in diameter, allowing her to enter small tunnels and openings, which often lead to previously inaccessible areas.

Samus has had several distinct movement systems and weapons at her disposal in Morph Ball form, most notably the Bomb. Morph Ball mode combined with some type of bomb is vital in defeating many bosses from the series, including Amorbis in Metroid Prime 2: Echoes and the Queen Metroid in Metroid II: Return of Samus. In non-Prime games, it usually plays an important role in escaping from enemies, such as in Metroid: Zero Mission. In almost every game, a combination of the Morph Ball and a Bomb is the only way to detach a feeding Metroid. In the three Zebes-based games, the item is almost immediately acquired by going left (from the sidescrolling perspective) after entering Brinstar.


Samus normal roll.gif

The Morph Ball has many upgrades, such as the Bomb Module, Cross Bomb, Power Bomb, Spring Ball, Force Ball, Boost Ball, and Spider Ball. Metroid Prime 3: Corruption introduces the new Hyper Ball ability, which allows Samus to generate deadly arcing tendrils of Phazon energy around her when in Hypermode. In Metroid Prime Pinball, the Morph Ball is the ball the player plays with on the pinball machine and introduces the Force Ball.


Samus transforms into the Morph Ball in Metroid Prime.

Throughout the series (most prominently in Echoes), the Morph Ball has changed in appearance according to suit upgrades. The Morph Ball when Samus is in possession of the basic Power Suit is a yellow or gold hue and has three grooves that spiral outwards from the center on each side. Between the two halves is a ball of energy, which is believed to be the essence of Samus. The energy varies in color depending on the suit Samus is wearing: With the Power Suit it is yellow, with the Varia Suit it is usually blue, green or white.

In Metroid Prime, the Morph Ball's structure changes with the acquisition of the Spider Ball: The edges of both halves become concave and filled by the same energy as the core, which is now green. The Morph Ball's color scheme changes twice more after this: When the Gravity Suit is acquired, it becomes purple with a blue core, and ultimately it becomes black with a deep red-orange core when Samus is infused with the Phazon Suit.

Concept art for the three Morph Ball designs in Metroid Prime 2: Echoes, the Varia, Dark and Light Suits.

In Metroid Prime 2: Echoes, after the Dark Suit is acquired, the Morph Ball becomes more wheel-like in appearance, in accordance with the shoulder pads of said armor. After acquiring the Spider Ball, a large red dot appears on sides of the Morph Ball. After the Light Suit is acquired, the Morph Ball becomes spherical again but has a spiraling groove on the sides.

In Metroid Prime 3: Corruption, the Morph Ball becomes a Phazon-blue ball with hexagonal tiles over it after the PED Suit is acquired. When the Hazard Shield is collected, extra plating is added to the Morph Ball. Also, if Samus touches a Liquid Phazon enemy while in Morph Ball mode, she will become engulfed by a portion of the creature, which will eat away at her suit.

In Metroid: Other M, the Morph Ball has a different appearance. The ball and energy are yellow with the Power Suit like in past appearances, but there are now three red stripes that spiral out from the center in the place of the grooves, making it closer in resemblance to the Fusion Suit's Morph Ball form. When the Varia Feature is authorized and activated, the energy becomes green and three shorter yellow stripes are placed alongside the red ones, similar to the small blue stripes on Dark Samus's Morph Ball. When the Gravity Feature is activated, the Morph Ball does not change since the Gravity Feature does not change the suit's color in this game.

In Metroid: Samus Returns, the Morph Ball undergoes a dramatic redesign: The spiraling lines are replaced by more linear grooves and rivets, while the edges are each encircled by a red ring. However, the Gravity Suit once again changes the color scheme to purple and blue.

Use by enemies of Samus Aran[]

Dark Samus's Morph Ball. Notably, the eye that appears on Dark Samus's hand at the end of Prime is present in the core.

According to a Space Pirate Data "Hunter Weapons" in Prime, the Pirates found the Morph Ball to be a very curious and intriguing technology, but attempts at reverse-engineering the Morph Ball technology all ended in a disaster: the Science Team "wisely decided to move on" after the first four test subjects were horribly broken and twisted after engaging their Morph Ball prototypes. The Pirates were successful in creating an Alt-Form for the Bounty Hunter Weavel however, in the form of the Halfturret. Instead of morphing, Weavel splits himself in two so that the upper half of his cybernetic body moves around and can fit through small spaces while the lower half becomes a stationary turret.

Dark Samus also possessed a twisted variant of the Morph Ball. She is shown using it in the second fight with her in the Sanctuary Fortress in Echoes, and she creates Dark Echoes which can use the Morph Ball during the fight with AU 313 at the end of Corruption. On both occasions, she uses the Boost Ball and is able to generate massive amounts of kinetic energy at once, which propels her around the area at shocking speeds. Dark Samus's Morph Ball is similar to Samus's and has an eye on each side in Echoes. It is very hard to actually make out the appearance of Dark Samus's Morph Ball in Corruption because it is always traveling at great speeds. The energy surrounding it while it is using the Boost Ball also obscures its appearance.

Dark Samus' Morph Ball also heavily resembles the Glire, Glice and Glunder enemies in Super Smash Bros. Brawl. The Morph Ball has limited appearances in gameplay as Samus; her rolling dodge has her literally roll aside to avoid attacks, and her Down-B special "Bomb" transforms her to the Morph Ball and drops the signature Bomb.

Methods of acquisition[]


Morph Ball trophy.png

The Morph Ball is available by default in Metroid Prime 2: Echoes, Metroid Prime 3: Corruption, Metroid II: Return of Samus and Metroid: Other M.

In nearly every game except Metroid Dread, the Morph Ball is usually acquired in the beginning of the game as either the first or second upgrade.

Official data

Victory Techniques for Metroid

"Maru Mari - Get this, and Samus' body will become round, allowing entry into narrow passages."
The Official Nintendo Player's Guide
"As soon as you start, go to the left. Jump up and cross the high walls, then you can get hold of the Maru Mari. This is useful for going through walls or narrow passageways."
Super Metroid manual
"You can use the Morphing Ball to make Samus roll into a ball and squeeze into narrow areas."
Super Metroid Players' Guide (Morphing Ball, page 9)
"When collected, this enables Samus to roll into a tight ball by pressing down when crouching, thereby allowing access to very small openings and tunnels. Location: Brinstar."
Metroid Fusion manual
"Use this power to roll into a ball and move through narrow passageways. Press down twice on the Control Pad."
Fusion website
"The Morph Ball ability allows Samus to roll into a small ball, perfect for traversing narrow tunnels or dropping down maintenance shafts."
Official Metroid Prime website
Weapon effect: N/A
Weapon range: N/A
Weapon potential: Medium"
"The Morph Ball is a modular upgrade to Samus Aran's Power Suit, allowing the bounty hunter to roll into a spherical shape. While in Morph Ball form, Samus can place Bombs, activate special switches and squeeze through tight spaces.
Like the Power Suit itself, the Morph Ball is upgradeable via several modifications located throughout Tallon IV.

Inventory data


Morph Ball

Metroid Prime Series

Inventory entry

The Morph Ball changes your suit into a compact, mobile sphere.
Press GC X button.png/Wii C button.png to enter Morph Ball mode.
Press GC X button.png/Wii C button.png again to leave Morph Ball mode.

Samus's Notes

Like the Power Suit, the Morph Ball is modular. There are several modifications that can be added to improve performance.

Metroid Official Site interview
"The Morphball is also an outstandingly original ability. It’s a really fun item to play with, but it also has many applications in the game. Since the Morphball’s design isn’t purposed for combat, the player can use it for transportation, to find hidden paths, or to solve puzzles. The Morphball really does differentiate this game from other FPS games, doesn’t it?" - Mark Pacini
"And it’s not just the visors; the Morph Ball is another important element that distinguishes Metroid Prime from different first-person games, but that was a big challenge. Around when we first started talking about the idea of Metroid Prime, we all thought that we just couldn’t make a Metroid game without the Morph Ball. What’s more, the way we designed the Morph Ball to be used made us all think that it should be presented in a third-person view. The switch to first person to third person was a tough challenge, but since it came out even better than we thought it would, we concentrated on what role we should give to the Morph Ball in the game. Comparing the Morph Ball with the first-person game state of Samus and her arm cannon, the Morph Ball was intentionally designed for the modes without combat. Since that round ball form doesn’t evocate a feeling of power, it doesn’t answer to the nature of combat. The Morph Ball is much more useful than that, and we positioned it as a key for the game’s strategy to be a cool item."[2]
Metroid Zero Mission manual
"This ability allows Samus' suit to curl into ball form and navigate narrow passageways. (Press down twice)"
Zero Mission Samus Screen data
"Double tap down to take ball form and gain access to narrow passageways."
Metroid Prime 2: Dark Echoes Q&A
QUESTION: What exactly happens [to Samus inside of it] when she is in Morph Ball mode?
ANSWER: The Space Pirates, too, are still searching frantically for the answer to that question...[1]
QUESTION: Previously in Metroid Prime 1, the Space Pirates went to great lengths to try to replicate Samus' suit technology, but in this installment there doesn't seem to be any activity like that. Will we be able to see Space Pirates in morph balls in the next game? Also, don't you think the Space Pirates who try to have Metroids as pets are a little messed up in the head...?
ANSWER: Between the Ing and Dark Aether, and being plagued by Dark Samus, the Space Pirates did not have enough time for experiments. If their experiments are successful by the next installment, maybe we can see some Space Pirates in Morph Balls... It seems that their scientific capabilities are strong...[2]
Metroid Prime Hunters Logbook entry
"SAMUS has the ability to transform into a ball that can move at high speeds and access areas her bipedal form cannot. To enter the alt-form, tap the icon in the lower corner of the touch screen. Use the +Control Pad or A, B, X, and Y buttons to move the MORPH BALL. Use the touch screen for more precise control with gentle strokes in the desired direction. BOOST by quickly stroking in the desired direction or by pressing the BOOST button."[3]
Metroid Prime Hunters Official Nintendo Player's Guide
"Samus can transform into a small Morph Ball that can move at high speeds and squeeze through the tightest of openings. It can also drop small bursts of volatile energy, which explode to damage foes or propel Samus upward."
Metroid Prime 3: Corruption on-screen tutorial
"You can use the Morph Ball to enter small spaces.
Press [C] to transform into the Morph Ball."
Metroid: Other M on-screen tutorial
With the Wii Remote held sideways, press [A].
Press [A] while in Morph Ball to return to normal.
Metroid: Other M manual
"Press A to go into Morph Ball mode and move around small spaces. Press A again to change back."
Metroid: Other M Samus Screen data
"Effect: Changes Samus into a ball shape.
Controls: Hold the Wii Remote horizontally and press A."
Brawl Sticker
Morph Ball Metroid Prime Pinball - [Weapon] Attack + 5 (Samus, Zero Suit Samus)
Super Smash Bros. for Wii U trophy description
"One of the numerous modules integrated into Samus's Power Suit. This one allows her to transform into a compact mobile sphere and explore tight spaces. In the very first Metroid game, it was known as the Maru Mari, which is just Japanese for "roll up," but it was later changed to the much-cooler-sounding Morph Ball."
Metroid: Samus Returns Samus Screen data
"The compact Morph Ball lets you move through narrow passages. Simply push [Circle Pad] down while crouching, or tap the map on the touch screen to take on Morph Ball form."
Metroid Dread Report Volume 5: The Powers of Samus
"Samus can pass through narrow passages by sliding—or by curling up into Morph Ball form.
The player can drop Samus into Morph Ball form by tilting the Left Control Stick down while crouching—effectively, the same way it’s always been done in the 2D Metroid series—and now also by simply pressing the ZL Button. Samus will also automatically take Morph Ball form when jumping into an elevated tunnel."
Nintendo of America tweet
"Samus can pass through narrow passages by sliding or by curling up her body to transform into a Morph Ball. You can now use the ZL button to transform, or it will activate automatically when you jump towards an elevated tunnel. #MetroidDread"[4]
Nintendo UK tweet
"Activating the Morph Ball ability lets Samus squeeze through small gaps that can’t be passed by sliding. Samus will use it automatically when entering raised narrow tunnels. #MetroidDread"[5]
"Enter Morph Ball form to roll through tight spaces, drop bombs, and more. Samus can automatically roll into Morph Ball form while sliding."
Metroid Dread Samus Screen data
Dread MorphBall Demo.gif Allows Samus to curl into a ball and enter narrow spaces.

Press Switch Dread ZL button.png or tilt Switch Dread left stick.png down when crouched to transform. While in Morph Ball form, press Switch Dread B button.png to jump.

When standing next to a narrow tunnel near ground level, press Switch Dread B button.png while moving toward the tunnel with Switch Dread left stick.png to automatically switch to Morph Ball form and enter. This also works while grabbing on to a ledge leading into a narrow tunnel.
Metroid Dread loading screen tip
Tilt Switch Dread left stick.png toward any Morph Ball tunnel near the ground, and press Switch Dread B button.png to switch to Morph Ball form while entering the tunnel.

Development notes[]

Nintendo originally gave Samus the Morph Ball for the original Metroid because technical limitations in the 1980s made it difficult to animate her crawling.[6] One player's question on Miiverse about Samus's inability to crawl led to the Y can't Metroid crawl? meme.

The Morph Ball's name from the original Metroid, Maru Mari, appeared in an early screenshot of its acquisition of Super Metroid.[7]

In Metroid Prime, the Morph Balls for every suit were modeled and skinned by Gene Kohler. Derek Bonikowski researched, animated and tested the Morph Ball in the Metroid Prime series. The third-person camera used when the Morph Ball is active was developed by Mark Haigh-Hutchinson, with the motion of the Morph Ball being developed by Scott Johnson.[8] When the Morph Ball moves slowly, it tumbles over itself, but rolls like a tire when moving quickly. Its movements were one of the final features of Prime implemented before its announcement at E3.[9]

Exactly how it functions is unknown, but Prime concept art shows a large ball forming around Samus from her suit's material, then shrinking down to its miniature size - in-game, a core of energy is visible through the equator between the two sides, indicating that Samus may transform into energy to fit into the smaller ball. Zero Mission design documents refer to the Chozo being capable of "unique transforming into a sphere," implying that the user's body is physically within the ball somehow.

In an Iwata Asks interview regarding Corruption, Kensuke Tanabe addressed the transition animation when un-morphing:

Originally, because Metroid Prime was an FPA game, the playable character was never seen on the screen. That's why we demanded they give the players the opportunity to have a good look at the character. We told them that, for example, when you turn into the Morph Ball, the camera should zoom back and show you Samus during the transformation. Even though it took a lot of effort, in the end, they managed to do it beautifully. However, at the time, if players wanted, they could skip this animation entirely. This may have been done in order to make the game play more efficiently, to save even a little bit of the player's time, but we felt, "If the player can just skip the animation, the original objective we gave you won't be fulfilled, will it?" This is why we requested they make the animation unskippable.

—Kensuke Tanabe

According to Clark Wen, the Morph Ball transition sounds in the Prime series are his favorite, and he wanted to get them right. The result in the final game is a mix of synths and processed recordings made to sound synthetic, as he thought the transformation between bipedal and Morph Ball forms was driven by electric magnets.[10] Wen went through seven to eight versions of iterations that were more mechanical in nature, and deemed too "normal" to exist in a science fiction setting. He settled on the magnet concept as it worked within the primarily synthesized sound design of Prime, and created the final sounds by combining effects in a sequencer. However, faint mechanical sounds were embedded into the final version.[11]

According to Colin Reed, the reflective surface of the Morph Ball in Metroid Prime Hunters was created by an unspecified artist who worked late into the night. However, he began to use the effect excessively in other areas, meaning they had to scale it down.[12]

Other appearances[]

The Morph Ball was slated to appear in Marvel: Ultimate Alliance along with Samus and several of her other abilities, however, they did not appear in the final game due to Nintendo not giving consent. The depiction in the trailer appears to be based on that of Prime as Samus charges forward several times, suggesting the Boost Ball was intended to appear as well.

The Morph Ball is featured in the Burger King toy Metroid Challenge, where the ball is controlled through a maze with a magnetic Wii Remote.

The Morph Ball makes a cameo appearance on the Geothermal Power Plant stage featured in Dead or Alive Dimensions, where Samus lays a Power Bomb when a sound is made in the microphone.

The Morph Ball, as well as Samus's tendency to use this technique, is indirectly alluded to in Animal Crossing: Wild World, where the character Gulliver, when mentioning that there were plenty of Bounty Hunters in space, alludes to one who can transform into a metal ball.


The Morph Ball Bombs are acquired in Metroid Prime 2: Echoes.

  • In the manual for Metroid, the Morph Ball is referred to as Maru Mari (marumari is the gerund form of the Japanese verb marumaru, meaning "to roll into a ball"). This name is also used in the Super Metroid Nintendo Player's Guide. This early name is referenced several times in later Metroid media:
  • The only time Samus ever demonstrated the use of the Morph Ball outside her Power Suit was in the original Metroid, when playing as suitless Samus. This was retconned by later installments; Zero Suit Samus crawls under gaps in Zero Mission and slides under them during the Countdown at the end of Other M.
  • In the Prime series, if Samus uses the Morph Ball before jumping from a high ledge, she will not be stunned from the fall like she would in bipedal form. This was extended in Metroid Prime Hunters, where all Bounty Hunter Alt-Forms, including the Morph Ball, take no fall damage unlike biped forms.
  • A visual glitch can occur where the morphing animation does not play out properly.

    In Metroid Prime 2: Echoes and Metroid Prime 3: Corruption, a visual glitch can sometimes occur where when Samus is morphing into Morph Ball, her animation isn't displayed properly and instead shows her simply standing in place attached to the Ball before her model disappears. This is usually performed when morphing into the morph Ball immediately after the cutscene pertaining to obtaining a suit upgrade. In Corruption's case, this glitch is easily seen when performing the Reverse corruption glitch, due to Samus's model readjusting to the Varia Suit.
  • In Other M, Samus will still breathe heavily when she is in Morph Ball mode if her energy levels are critically low.
  • The Morph Ball ability is shown in a manga panel for Nintendo Official Guide Book for Super Metroid, which shows Samus in the position and humorously mentioning an uncontrollable urge to urinate.
  • Although the morphing animation itself is not normally skippable manually, there are a few instances in Metroid Prime 2: Echoes and Metroid Prime 3: Corruption where the animation itself is skipped and instead goes into instant morph/unmorph (a prime example being the use of the Bomb Space Jump). This is most likely contributed to adjusted camera angles.
  • In Dread, Samus has an animation where she presses her left hand to a wall when close to one. When she is close to a gap she can morph into, her hand will either be positioned above the gap if she does not have the Morph Ball, or in the gap if she does.[13] The latter position allows for a smoother transition into her Morph Ball animation.[14] When emerging from a small tunnel, if the directional analog stick on the Joy-Con is held, Samus will automatically unmorph. If the stick is released while she is in the tunnel or she jumps, Samus will remain morphed when she exits the tunnel.[15]
  • The speed of the Morph Ball varies greatly between games.
    • In earlier 2D Metroid games, it is roughly the same speed as when Samus walks normally. In Super Metroid however, Samus can speed it up all the way to her running speed using the Mockball glitch, and in Metroid: Zero Mission she can propel herself with the Ball Spark.
    • In the Prime series, it is considerably faster than Samus' bipedal form, especially when she uses the Boost Ball. This increased speed sometimes becomes necessary to dodge boss attacks such as Quadraxis' matter-antimatter blasts or the ramming attack employed by later Slench models.
    • In Metroid: Samus Returns and Metroid Dread, it is considerably slower than running normally, especially in the latter game which has the slowest Morph Ball in the series to encourage use of the slide move. However, Samus can still move extremely quickly in ball form using the Power Bomb Cannon in Samus Returns or the Speed Booster and Ball Spark in Dread.




  1. ^ The Official Nintendo Player's Guide, page 53
  2. ^ " Interview: Retro Studios", Shinesparkers, 2021-02-26. Retrieved on 2021-02-26. 
  3. ^ Metroid Prime Hunters Logbook
  4. ^ Nintendo of America (NintendoAmerica). 24 August 2021 1:00 p.m. Tweet.
  5. ^ Nintendo UK (NintendoUK). 26 August 2021 8:00 a.m. Tweet.
  6. ^ Thomas, Lucas M. "Six Things You Didn't Know About Metroid's Samus Aran". IGN. July 22, 2011. Retrieved June 10, 2022.
  7. ^ Kottpower. "Super Metroid Beta Footage (1993-1994)". YouTube. August 25, 2017. Retrieved May 25, 2022. (starts at 2:16)
  8. ^ Kiwi Talkz. "#116 - Jack Mathews Interview (Metroid Prime Trilogy, Prototypes, Business, Armature Studios etc.)". YouTube. November 26, 2021. Retrieved June 8, 2022. (starts at 35:06)
  9. ^ Crackdown. "Extra Life 2015 (Part 2)". Twitch. December 7, 2015. Retrieved June 10, 2022.
  10. ^ Interview: Clark Wen. Shinesparkers. 2018-06-02. Retrieved 2018-06-02.
  11. ^ Kiwi Talkz. "#112 - Clark Wen Interview (Metroid Prime, Sound Design, Kenji Yamamoto, Mixing, SFX, Game Audio )". YouTube. October 23, 2021. Retrieved April 24, 2022. (starts at 6:00)
  12. ^ Colin Reed: "It was one artist just hammering away in the middle of the night. He comes to show us what he did, and we were like, "Oh that's cool, let's use that." (laughter) Then the effect just spreads off and starts getting used all over the place. Then we have to reel them back in and say, "Ok. No, he's using it too much." Nintendo World Report.
  13. ^ Looygi Bros. "10 Cool Details in Metroid Dread (Part 2)" YouTube. December 11, 2021. Retrieved December 14, 2021.
  14. ^ Video Game Animation Study. "The Brilliant Animation in Metroid Dread" YouTube. November 29, 2021. Retrieved December 14, 2021.
  15. ^ Looygi Bros. "12 Cool Details in Metroid Dread (Part 9)". YouTube. February 1, 2022. Retrieved February 2, 2022.
  16. ^ Sakurai, Masahiro (Sora_Sakurai). 11 September 2020 11:00 p.m. Tweet.