Jesus, santa, god, Freddy Krugar (Inception parody episode), Leprechaun am I missing someone else?
Those first 4, as I already said, only exist in imagination land. AKA imagination. Well, Jesus probably really did, but the idealized version they use is not.
I'm saying only the leprechaun has shown itself in the real world. The Jesus from the show... I'm not sure if he came to the show as imagination, or there's an imagination version...