Metroid larva

A Larva Metroid, or Generic Metroid is the third stage of the Metroid's life cycle. It is the most common and recognizable form of the species in the series of the same name, making it iconic. In fact, the larvae are encountered so often that they are usually referred to as simply "Metroids". Larva Metroids are extremely ravenous and are constantly seeking to eat as much life energy as possible.

The larvae possess unique biological traits that make them a favorable specimen over the later stages of their life cycle for bioweapon research and experiments.

Physiology and morphology
The body mostly consists of a thick, round, translucent membrane resembling a jellyfish's hood, typically ranging in colors such as blue, green and sometimes red. Within this membrane can be seen four red, spherical organs resembling nuclei, closely arranged so only three can be seen from most angles. Many neuron-like connections grow out of them and attach to the membrane's inner surface. The creature's fleshy, leech-like mouth lies underneath the membrane, and features two pairs of mandibles: the larger pair for gripping their prey, and the smaller for siphoning out its life energy. Metroid larvae appear capable of directly sensing the life energy of their prey, despite having no recognizable sensory organs. Similar to most other forms of Metroid, they are capable of flight despite lacking any visible means of propulsion.

Similar to the larva of insects, Larva Metroids are highly ravenous and will feed on any and all living creatures they encounter, with the exception of their own species. They can also feed on the energy from artificial life forms and technology. Once attached to their prey, the Metroids are nearly impossible to dislodge and will quickly drain their victim's life force completely, often killing it in seconds. Using Morph Ball Bombs is the only known way of dislodging an attached Metroid; consequently, Samus is one of the only two beings capable of surviving Metroid attacks, the other survivor being Mother Brain using an unknown 'resurrection' ability. It can be assumed that their hunger is driven by a need to fuel the metamorphosis to the next stage(s) of their life cycle. However, Metroids have demonstrated the capacity to heal wounded organisms by giving them life energy drained from other victims, as seen with the baby in Super Metroid. The life energy stored in a Larva can also be drained and used for other purposes, allowing the creature to be used as a living rechargeable power cell. However, a scan in Metroid Prime 2: Echoes reveals that repeated energy drains can cause cellular breakdown to occur in the Metroid.

Contrary to all later stages in the species' life cycle, a larva's membrane is extremely durable. In fact, no conventional weapon is capable of wounding the creature unless it is first exposed to its major vulnerability: cold temperatures. Metroid larvae tend to become sluggish in frigid conditions, and their membranes are easily frozen solid, allowing the creatures to be shattered and killed by concussive weaponry such as Missiles and Super Missiles. Power Bombs can also sometimes harm them, though their level of effectiveness varies widely. Though it has yet to be explained why the membranes of older Metroids can be readily harmed without the need to freeze them first, it is worthy to note that only Larva and Infant Metroids possess four nuclei. The later Alpha, Gamma, Zeta and Omega Metroids have lost all but a single nucleus, which not only suggests that this affects the membrane's defenses, but also that the missing nuclei were used for the creation of the new bodies observed in the stages following the Larva Metroid form. The nuclei could thus be interpreted to have a similar function to stem cells.

An additional trait that is seemingly restricted to the Infant and Larva stages, is their ability to asexually reproduce via division, much like a cell undergoing mitosis, when exposed to Beta-rays. Thus, their numbers can increase without the need of a Queen Metroid laying Metroid Eggs.

Adaptations and mutations
One of the most concerning qualities of a Larva Metroid is its capacity to adapt on any planet (with the exception of those with global sub-zero climates). A foreign planet's atmosphere and environment can trigger the Metroid's body to go through either subtle or drastic physical changes, allowing the organism to efficiently hunt alien life forms without hindrance. This adaptation is not without consequence as the larva will be unable to metamorphose into its natural advanced stages observed on its homeworld of SR388.

To further complicate matters, the Larva Metroid, which is meant to be a voracious but temporary phase, is now trapped in a perpetual state of hunger. This puts an alien planet at great risk, as a small number of insatiable Larva Metroids could potentially wipe out all life on it. This threat is compounded by their invulnerability to most forms of weaponry as well, which makes dealing with the invasive Metroids an extremely difficult task for the native inhabitants.

Interestingly, it is the Larva Metroid's inability to molt outside of SR388 that caused the erroneous belief that the increasingly common larval, jellyfish-like phase was the standard form of the entire species, unaware of the fact that further developed Metroids could be found in the unexplored homeworld.

The above dangerous traits, along with the previously mentioned ability to increase the Metroids' numbers with Beta-Ray exposure, are what caused the Space Pirates to gain such a high interest to use the larvae as bioweapons in the first place. Within a few years, research and experiments performed on their near-limitless supply of specimens led to the creation of mutants by using radioactive elements such as Phazon. Each aberration possesses unique qualities and some manage to escape their larval phase entirely despite adapting to a foreign planet, allowing the Metroids to further mutate. In time, the Galactic Federation itself would begin seeking to use Larva Metroids for its own purposes as well.

For a complete list of the species' unnatural strains created by exposing Metroid larvae to several elements, direct cloning, symbiotic takeover and importing the organisms to alien planets, click here.

Metroid manual
"This protoplasm in suspended animation was discovered on the planet SR388. It clings onto Samus' body and sucks his energy. It can't be destroyed directly with the normal beam. Freeze it with the ice beam, and then fire 5 missile blasts at it."

Virtual Console retranslation
"This protoplasm, discovered on the planet SR388, clings to Samus and drains her energy. It can't be defeated with a normal beam, just repelled. Use a combination of the Ice Beam and missiles to defeat it."

Official Nintendo Player's Guide
"This is a mysterious life form which was discovered on the planet SR388. It sticks to Samus’ body and sucks out her energy."

Metroid II manual
"This is their first shape after hatching from eggs. They will cling to any creature that they can find, drawing its victim's life energy away."

Super Metroid manual
FLOATING LIFE FORMS - METROIDS

"It is said that Metroids are life forms created by an ancient civilization. Metroids engulf living creatures and absorb their energy. They are very intelligent and quick to reproduce."

Super Metroid Nintendo Player's Guide
"Freeze them, then blast them with Super Missiles."

Official Metroid Fusion website
"These energy-based creatures have the ability to absorb the life force from any living thing. As the natural predator of X-Parasites, however, the Metroid may now be the key to Samus's survival."

''An energy-based life-form with a translucent, spherical upper body. Claw-like spikes protrude from the lower-half of the creature, which it uses to latch onto its prey."''

Metroid: Zero Mission manual
"Metroids are the floating organisms discovered on planet SR388. These fearsome predators latch onto other organisms and leech the life energy out of their prey."

Official Metroid: Zero Mission website
"SPECIMEN ID# M-1A

"Extremely dangerous! Gelatinous exterior of Metroid makes it impervious to beam weapons. Metroids can only be destroyed by Missiles while frozen. Large claws grip prey while smaller front fangs drain its life force. Transform to Morph Ball and use Bombs to escape grip. DANGER LEVEL: HIGH"
 * "Gelatinous exterior"
 * "Multiple brain stems"
 * "Gripping claws" (Outer)
 * "Energy-sapping fangs" (Inner)

Official Metroid Prime Website
"Metroids are highly dangerous parasites averse to cold temperatures. The dominant species of planet SR388, Metroids can suck the life force out of living things. A Metroid will latch onto its prey and drain energy, growing larger as it does.

Metroid Prime Pinball manual
"An energy based, highly dangerous parasite."

Smash Tips
"These alien creatures float around and then try to clamp down on you with their sharp fangs. Quickly struggle to break free from their grasp."

Smash Tour (SSB4 Official Game Guide)
"Lasts 5 turns or until a player bumps into it two times"

"Bumping into this enemy costs you several stat boosts! Reclaim lost stat boosts by bumping ino it a second time."

Appearances in other media



 * Metroids appear in the Kid Icarus franchise, under the name Komayto, which is stated in the instruction manual to have come from another planet. This creature can be found flying around Skyworld in packs. Kid Icarus was also created using the Metroid game engine. During the game Kid Icarus: Uprising, the main character Pit states himself that "Komaytos kind of look like little Metroids" before being hushed by Viridi.
 * A Metroid is a collectible treasure in Wario Land II. They are also often in 9-Volt's microgames in the WarioWare series, such as WarioWare, Inc.: Mega Microgame$!, WarioWare, Inc.: Mega Party Game$!, WarioWare: Touched! and WarioWare: Twisted!.
 * Metroids made an appearance in Kirby's Dream Land 3 for the SNES. If Kirby freezes all the Metroids in the level, Samus removes her helmet and gives Kirby a Heart Star.
 * Metroids wander onto stages randomly in Metroid Prime Pinball and also have their own minigame, Metroid Mania.
 * In Metroid Prime 3: Corruption, a Metroid is used on the tab for the creatures section of the Logbook. Interesting to note is that the Metroid depicted here has six nuclei, five encircling the top of a larger, centralized nuclei.
 * The Baby from Metroid II: Return of Samus and Super Metroid appears as an item in the Nintendo DS game Animal Crossing: Wild World. It appears in its signature capsule, and if tapped will play a few seconds of the Super Metroid title screen theme. It is a rare item that is acquired randomly by shooting down Gulliver. The item also appears in Animal Crossing: City Folk, but cannot be transferred through the ingame catalogue due to the item's rarity. It acts the same way as before and is obtained in the same manner as well; it will play the entire Super Metroid theme this time however. The same item appears once again in Animal Crossing: New Leaf, but it is not obtained through the same method as the two previous games. Instead, it is randomly acquired through fortune cookies, which the player can buy using two of the 3DS's Play Coins. This version also plays only a few seconds of the title theme.
 * In Tetris DS, there is a single player game mode called Catch Mode where players catch Tetraminos (blocks) in order to create a 4X4 square and detonating it to make the cluster smaller. The Brinstar theme plays during this and encapsulated Metroids (in capsules similar to the Metroid hatchling's) fall down. If touched, the energy meter will go down and the cluster becomes smaller.
 * A Metroid can be seen on Nintendo Monopoly representing St. James Place for $180.
 * A Metroid is shown in a capsule in Singularity along with the message "Mother my brain hurts".
 * A Metroid is seen in a tank in Starcraft 2: Wings of Liberty in the secret Mission "Piercing the Shroud." It is very similar to that of the baby.

Super Smash Bros series

 * Metroids appear in a minor reference in Super Smash Bros., in Super Smash Bros. Melee as a trophy as well as the baby being seen in the opening cutscene, and in Super Smash Bros. Brawl and Super Smash Bros. for Nintendo 3DS and Wii U as an Assist Trophy that will latch onto opponents and "drain" them of energy (what they actually do is increase the victim's damage, but can still sap health if a stamina match is being played). It can be shaken off, which will cause it to try and seek another victim. It can phase through platforms similar to a Phazon Metroid. Using Up-Special moves while the Metroid is latched on to a character cancels the move after the few starting frames; this can be done multiple times in a row. This allows some characters to stay in the air for quite a while. Interestingly, the model of a larval Metroid used in-game for the Nintendo 3DS and Wii U games exhibits unnaturally large inner-fangs; in fact, they appear to be larger than the outer ones. In Melee, the intro scene from Super Metroid is reflected off of the trophy, with the infant missing from the scene.

Super Smash Bros.
Metroids are briefly mentioned in Samus's "Characters" bio in the "Data" section of SSB. Her bio says that Samus "...pursues the airborne life form, Metroid, throughout the whole universe."

Super Smash Bros. Melee
"A parasitic life form that can absorb all types of energy, Metroids have strong resistance to most conventional weaponry. To defeat them, Samus Aran had to freeze them with Ice Beam shots and then blast them with missiles. Mochtroids, which look like Metroids, are weaker, with fewer internal nuclei."

(Metroid 08/89).

Super Smash Bros. Brawl
"A bioengineered life-form found on planet SR388. Metroids attach to organisms and drain life energy. The Galactic Federation commissions Samus to eliminate them, but Space Pirates try to harness their power. One of the few ways Samus can kill Metroids is by shooting them with the Ice Beam and then shattering them with missiles. The Metroid's cry is chilling and indescribable."

Metroid (1987)

Metroid II: Return of Samus (1991)

Smash Bros. DOJO!! data on the Assist Trophy
"Like the name says, this Assist Trophy is from the game Metroid. It's an artificial life-form that absorbs all kinds of energy.

''In our game, it also attaches to the head and starts to drain its victim. Since it will increase your damage, try to shake it loose."''

Stickers

 * Metroid Metroid Prime Pinball - [Freezing] Attack +18 (All)
 * Metroid Metroid: Zero Mission - [Electric] Attack +20 (Samus, Zero Suit Samus)

Super Smash Bros. for Nintendo 3DS and Wii U Trophy

 * NTSC
 * "First discovered on planet SR388, this floating life-form grows by absorbing the energy around it. It is incredibly durable but extremely weak to cold. In Smash Bros., a Metroid will grab a rival by the head and drain energy. If you get grabbed, shake it off by pressing left and right!"


 * PAL
 * "Mysterious floating life-forms, discovered on the planet SR388, that absorb energy from other living beings. They're tough, except when they're cold. In this game, they'll try to attach themselves to fighters' heads and drain their energy. Press all the buttons you can to shake them off!"

Nintendo Land
Metroids appear as robots. They can suck out the Mii's energy but they also like to drop Miis in the Lava on the volcano map. Metroids must be frozen with the Ice Charge before shooting their core to kill them, reminiscent of how they are killed in the official Metroid games. This game also implies that the Chozo went extinct because they lost control of the Metroids.