Breadcrumbs

[angelina107]

This is the Old Man. He guards the dungeons in Terraria. When you talk to him, he tells you that you can't enter without freeing him from his curse. And if you try, the Dungeon Guardian (an over-sized, flying skeleton head) will rise from the dungeon depths, hit you, deal 9000+ damage (No joke, "Over 9000"), and you die.
At night, you'll find that you can fight him. When you choose this option, he turns into Skeletron. And if you manage to defeat Skeletron, you can now enter the dungeon without the Dungeon Guardian coming up to kill you. Along with this, the Old Man is now freed of his curse and is now your Clothier (assuming you have made a house for him. Whether you built it before defeating Skeletron or after does not matter.)
Old Man, Dungeon Guardian, and Clothier belong to Terraria Wiki and all rights go to them. The Skeletron-fight picture's rights go to it's respective owner.