Gohma

In Ocarina of Time
The mother of all arachnids inside the first dungeon and the "curse" placed upon the Great Deku Tree, Queen Gohma, the Parasitic Armored Arachinid, is your first boss in OoT. Not so hard as you might think, Queen Gohma's only weakness is her eye when it turns red, but don't just rejoice, not for nothing her title reads "armored" and anywhere else (even her normal eye) but the red eye will result in a useless attack from you. She has just two ways of attacking you: one is the very first thing she does when the fight begins, Queen Gohma will climb into the ceiling, and from there lay some eggs into the ground (Just before laying the eggs her eye will turn red). The eggs will turn into Gohma Larvae if you're not fast enough to destroy them before they hatch. The Gohma Larvae, as you might know from previous experience inside the dungeon, attack in only one way: when their eye turns red, they will attack by jumping towards you. The second way is by walking menacingly towards you and hit you with her pincers (Again just before she does this, she will "stand up", scream and turn her eye red). As soon as you enter the room, whip out your slingshot and Z-Target her eye. When it turns red, shoot it and she will be stunned for a few moments. This gives you the opportunity to hack away with your Kokiri Sword. If you don't defeat her the first time, Z-target her again as soon as she get up, and wait until she's up on the ceiling. She will try to unleash her babies on you; when her eye turns red, unload with your slingshot. However if the babies still come, Z-target them and defeat them quickly. When Queen Gohma comes back down, continue with the same pattern as before to defeat her and earn your prize: a Heart Container and the Spirtual Stone of Forest, the Kokiri Emerald, which the Great Deku Tree will give to you.

In The Wind Waker
When Link arrives to Dragon Roost Island to get Din's Pearl, Link finds out that in order to do this he must help the Rito, a bird-like race, as well, with their Guardian Spirit of the Sky, Valoo, which seems to be quite angry for some reason. As Link roams the dungeon inside Dragon Roost Cavern, he finds out, as Medli tells Link, that there is "something" harming the Great Valoo's tail. In a short while, Link discovers that an impressive, lava-resistant, insect-like monster is the one responsible for this. Gohma is its name and much for Link's "luck", he must fight it. The first obstacle to inflict any significant damage is to get rid of Gohma's hard shell. First, use your grappling hook on Valoo's tail that is sticking out of the ceiling, do a good swing and let it off where you can land on a safe spot (it's better if you can land in one of the wooden platforms along the stone wall) and watch the ceiling cave in over Gohma. Do this another two times and Gohma's shell will be destroyed, leaving its weak spot, its eye, vulnerable. Use the grappling hook on Gohma's eye to bring it down to your level and attack with your sword to defeat it. Once you achieve this, you'll receive your prize: a Heart Container and an apology as well as Din's Pearl from the Chieftain's son, Komali. In The Wind Waker, you must defeat Gohma twice, once in Dragon Roost Cavern and once in Ganon's Castle to complete the game.