The Shrine of Illusions is an altar found in the basement of the Wizard’s Tower. The player can offer500g to the shrine to change their appearance, name, favorite thing, gender, as well as the appearance (but not type) of their pet.
The Wizard’s basement becomes accessible from a trapdoor in his house when the Player has at least four hearts with him. It can also be accessed through a red portal in the Witch’s Hut as soon as the Witch’s Hut is accessible.
Trivia
Changing the character’s name to include item spawn codes triggers an Easter egg.
Changing the favorite thing to be “ConcernedApe” or anything containing “Stardew” gives special dialogue when collecting a stardrop