Gohma is an evil monster that has appeared as a boss throughout various The Legend of Zelda games. Though it has appeared in various forms depending on the game such as a crab, a spider and an antlion for example; they all resemble arthropods with a single eye, its weak spot.
The Legend of Zelda
Gohma makes its first appearance as a boss in the very first Zelda game. Appearing as a crab with a single, large eye - Link must shoot an arrow to its eye to defeat it. Stronger Gohmas are encountered as "regular" enemies in later dungeons, needing several arrows to be destroyed.
Two Gohmas, resembling those of the first game appears as minibosses in Level 5 Catfish's Maw. The method is the same: shoot an arrow to their eyes several times to defeat them. If you're out of arrows, Link's Hookshot also gets the job done.
Ocarina of Time
Gohma appears as the first boss in Ocarina of Time. In this game, Gohma was placed inside The Great Deku Tree as a curse inflicted by Ganondorf. It appeared as a spider-like creature with a large blue eye. To defeat her, Link had to shoot Gohma with the slingshot when its eye is red and attack her eye.
Oracle of Seasons
Gohma appears as a boss of Level 4: Dancing Dragon Dungeon. Again, its appearance is like that from The Legend of Zelda and Link's Awakening with an oversized claw, but do not be fooled - Gohma is one of the most formidable bosses in the game. If Link gets caught in its gigantic claw, it will slam him against the floor several times substracting up to four hearts. Gohma also spawns larvae of many colors. To defeat it, Link must cut off his claw with the sword and then fire at its eye with the slingshot.
The Wind Waker
Gohma also appears as the first boss in The Wind Waker. It appears as a giant, magma covered scorpion, with a large blue eye. It was placed in Dragon Roost Cavern to torment the great sky dragon, Valoo. To defeat it, Link had to pull the ceiling of the cavern down on his head to break his armor coating. He, then, had to attack his eye.
Gohma appears as a boss in Hyrule Warriors.