Skulltula

These huge spiders hang from the ceiling and surprise you by dropping down and attacking you. If you go near them, they will spin around, causing you to fly away whilst getting hurt. To kill them, wait until they turn around to bear their soft belly, then attack with your sword. An alternative is to use the Hookshot. A special type of Skulltula that appears in Ocarina of Time is the Gold Skulltula, who drop gold skull tokens that can be traded for usefull items such as the upgraded wallets in a house in Kakariko Villiage. Although they look different in each game, one constant is a skull-like shell.

In Twilight Princess, they block every one of your attacks until they are stunned with a shield attack, or when they attack, you jump aside and slash them. Or, you can defeat them by first stunning them with a Spin Attack, and then finishing them off with the Ending Blow. When you kill them, and you sheath your sword, Link will sheath his sword like would when he kills a boss.

Skulltulas return in Phantom Hourglass, as residents of the Ghost Ship. They look largely the same as their Ocarina of Time and Majora's Mask incarnations, but are much easier to kill, requiring only a single swipe of Link's sword. However, they are much more annoying than before, since they respawn much faster than normal enemies, and drop down from the ceiling to attack with little warning. The Cubus Sisters are deathly afraid of the spiders, cowering and screaming whenever they appear (although they might pretend to be in order to send the Reaplings after Link). They're so scared of them that the mere sight of a Skulltula causes them to freeze, hampering Link's rescue effort by forcing him to run back and offer reassurance.