Gohma

Gohma (also known as Ghoma, but henceforth referred to as Gohma) is a recurring boss in the Legend of Zelda series. Its incarnations are all armored crab/spider creatures that are characterized by its tell-tale large eye.

Gohma's role in The Legend of Zelda
In this game, Gohma was a simply a large armored spider creature with an enormous eye that was susceptible to arrows. In order to defeat it, simply shoot his eye several times. It is considered to be the mother of all Tektites.

Gohma's role in The Legend of Zelda: Ocarina of Time
Parasitic Armored Arachinid: Gohma is as the description implies, a spider. Queen Gohma that is part of the curse on the Great Deku Tree. To defeat it, wait for Gohma to climb down to the the floor and throw a Deku Nut at her, or use the Fairy Slingshot. Then, slash the eye. Repeat until Gohma is dead.

Gohma's role in The Legend of Zelda: Oracle of Seasons
This incarnation is very similar to that of the original The Legend of Zelda, however, it more resembles a crab than a spider, complete with quick sideways movements, and crab-like claws. He is fought mostly the same way as the original. However instead of immediately shooting it's eye with arrows, one must first slash and destoy its prominent claw and then shoot seeds into its eye with the slingshot.

Gohma's role in The Legend of Zelda: The Wind Waker
This Gohma is arguably the most different one. While other Gohma's seemed to be more spider, this one seems to be more crab and even more centipede. Similar to its other roles, it is sometimes assumed to be the mother of all Magtails. While the other Gohma's focused on shooting projectiles into its eye, in the Wind Waker, you don't even directly attack it until halfway through. With the newly acquired Grappling Hook, you must first Grapple to the swinging tail of Valoo above it. Once attached, you swing across the stage and a piece of rock breaks free and smashes Gohma, damaging his shell. Once repeated several times, the shell will break, and you are free to attack Gohma with your sword as you please (until it dies).

Gohma's role in The Legend of Zelda: Twilight Princess
Gohma appears as Armogohma in Twilight Princess and is the boss of the Temple of Time. She appears as a large tarantula with a large, sinister eyeball on her thorax. This eyeball fires a laser beam at Link and also serves as Armogohma's "weak point" (Link must fire an arrow at the eyeball to make Armogohma fall to the floor; when she does, Link takes control of a statue using the Dominion Rod and crushes Armogohma). As in her Ocarina of Time form, Armogohma gives birth to several little spiders who attack Link. Armogohma's second form is just her eyeball carried by some of her young.

Gohma vs. Ghoma
For each of these bosses, both spellings are used interchangeably. It is used so much so that if there was a distinguishable difference between Gohma and Ghoma it's not present anymore. But due to the similarity of the bosses regardless of the name, they are usually considered by the same name.