Skeleton

Skeletons spawn in the Cavern layer. They follow the Fighter AI, and can open doors. Unlike Zombies, they do not require a Blood Moon to do so. They can drop a Hook which is essential for making a Grappling Hook

Skeletons are immune to the Poisoned debuff.

They can also be spawned by powering a Skeleton Statue.

Trivia
Skeletons appear in at least 13 different forms in the game, being: The 4 Skeleton forms, the 4 Angry Bones forms, Skeletron, Skeletron Prime, Skeleton Archer, Undead Miner, and Armored Skeleton

History
Squelette Skeleton Skeleton Скелет