Bone Key

The Bone Key summons a Baby Skeletron Head pet that follows you until you cancel the buff icon, like other pets. It is dropped by Dungeon Guardians. Because Dungeon Guardians have insanely high stats intended to instantly kill most players, this is an extremely difficult item to acquire.

Tips

 * Bringing turtle armor from a hard mode world is an easy way to kill the dungeon guardian.

Trivia

 * The buff description states, "Don't even ask... "