Goyagma (ゴヤケード Goyakēdo ) is a boss creature in Metroid: Other M. It is fought in the Crater Interior of the Pyrosphere, seen rising up out of a pool of lava. Goyagma appears to be a dragon-like creature with clawed hands and tentacles. Right before the battle starts, Adam authorizes Samus's Varia Feature, although defeating Goyagma itself grants no rewards beyond draining the lava and opening a new path into the Pyrosphere.
Before the battle, Samus races up to the top of the volcano, due to rising lava. The Goyagma will attempt to grab her and drag her into the lava to kill her. This, coupled with the rising lava, enemies in the way and lack of the Varia Suit make it a very difficult journey. At the top, the Goyagma will grab Samus, at which point she must unleash a charged shot to break free.
It has a pulsating red neck, which is its weak spot. Samus must target the neck with her Ice Beam and freeze it, then shatter it with a Missile. This must be done twice. Then, the creature covers its arms with flames and will start trying to slam its hands into Samus while pillars of lava come out. Eventually, the creature will tire out, leaving one of its hands vulnerable. Samus then can freeze one of the hands, which will also freeze the arm. She can run up to the arm and jumps on the side of the creature's head and pull herself on top of it to perform an Overblast to inflict severe damage. Afterwards, she jumps off the creature and must repeat the process two more times. When defeated, the lava sinks.
Interesting to note, when performing the last Overblast, the Goyagma will attempt to slam her with its hands. As it attempts to slam her after she pulls herself on top of its head, Samus jumps and lands on the hand, which then launches her and the Goyagma attempts to catch her but misses, ultimately leading Samus to deal the final blow on the back of the beast's head to defeat it.
Its attacks include throwing flames, sweeping with its large arms, and launching globs of burning gel resembling flaming Boyons. It can also submerge itself in lava to instantly remove the ice particles it has received on its neck. Also, when the Overblast is performed a second time, the Goyagma can "trick" Samus by slamming its hand down once and then sweeping the area with the free arm.
- When the Goyagma grabs Samus at the top of the Crater Interior, the charging rate is heavily reduced regardless of how many Accel Charges she has.
- When the Goyagma grabs Samus and when Samus performs the first two Overblasts, the player does not need to do anything as Samus will automatically perform the reaction. The player does, however, needs to manually fire the shot at the third Overblast, or it will slam her down to the ground.
- If Samus targets the vulnerable hand in Search View, she is prompted to fire a Missile.
- Despite that Samus is intangible during SenseMove, the Goyagma's arm sweep can hit her in mid-animation. The Queen Metroid is also capable of this with its fire breath.
- Seeing how the Goyagma's arms wiggle and curl, this creature would be an invertebrate, as it would be impossible for a creature with bones to move in such a manner.
- Goyagma's name may be derived from gargoyle, given its grotesque look, and magma, which the creature dwells in.
- The third Overblast on the Goyagma could be considered a Lethal Strike.
- One interesting feature about Goyagma is that in the beginning of the battle, it has six projections on its neck, but after its neck is frozen and hit by a Missile twice, it will lose the two bottom projections.
- When the Goyagma is defeated and the body starts deteriorating, the head of the Goyagma can be seen dislodging itself from the rest of the body and falls into the lava.
- Goyagma's arena is very similar to the arena of the Typhon boss from Rygar: The Lengendary Adventure and Rygar: The Battle for Argus. These two games were made by Tecmo, who also helped to co-develop Other M. It's possible that the arena that Goyagma is fought in was based after the design of the Typhon's lair.
- Concept art of Goyagma states that its weak point is located on its spine, meaning that Samus actually fights it from behind. Concept art also reveals that it clings to rocks in the lava-filled volcano, where it eats bedrock using its soluble saliva.
- Goyagma shares its battle theme with the first battle against Nightmare in Other M.