Walltula

Skullwalltulas haunt the vegetation of Ocarina of Time, Majora's Mask and Majora's Mask}. This arachnid creature clings on vines waiting for enemies to climb up. If the enemy is deemed hostile or a threat, the Skullwalltula will flash purple and scurry over to the target, knocking it off the vine. The Skullwalltula resembles a Gold Skulltula in appearance (other than the skull plating, which resemble normal Skulltula), and they also make the same sort of scratching sound. They can easily be dispatched with any ranged weapon including the Hookshot, Boomerang, and Bow. The shock waves produced by the Megaton Hammer when it strikes the ground at the foot of a wall covered with Skullwalltulas will also work surprisingly well. It is usually necessary to destroy these creatures before climbing up a vine, as their scurrying attack is extremely hard, if not impossible in some places to avoid.

Ocarina of Time
Skullwalltulas are found in many places in Ocarina of Time. Just about anywhere that there's a collection of vines that Link can climb up, there's a Skullwalltula waiting for him. Various places include inside the Great Deku Tree, the Forest Temple, and other temples.

Majora's Mask
Skullwalltulas are a rarity in Majora's Mask. They only appear in a nearby hole near the giant tree with Skull Kid's drawing in Termina Field. There aren't many varieties of Skulltula found in Termina at all, so it's not much of a surprise to most.

Twilight Princess
Spiders which look and behave similarly to Skullwalltulas can be found clinging to walls and vines in Twilight Princess. One shot from the Bow, Slingshot, or Clawshot is all it takes to slay them. While likely a close relative, these spiders do not have the characteristic skull pattern on their back, and thus are simply called Walltulas.

Skyward Sword
In the presentation video of Skyward Sword, Walltulas can be seen climbing on the vines of a wall, although they appear to be moving faster than their Twilight Princess counterparts. Link can easily take them out using the Slingshot.

Trivia

 * Skullwalltulas will only charge Link if he moves while they are facing him. At all other times, they will ignore him.
 * In Ocarina of Time, when a Skullwalltula falls to the ground and before its body burns, the Megaton Hammer can be used to make the creature bounce, as if killing it again. By this, it is possible to "juggle" a Skullwalltula's body on the ground indefinitely.