In the universe of Neil Gaiman's "Sandman" comic books, Delirium is the youngest of the seven Endless. She used to be Delight, until something occurred which not even her oldest brother Destiny knows that caused her to change.

Delirium has one blue eye and one green eye, typically. She's given to talking in a complete stream of consciousness and has great difficulty holding on to two different thoughts at the same time. Her appearance changes regularly, except of course for her eyes, and her realm is one of disorder and madness. Indeed, all mad people are of her realm.

She has a talking dog named Barnabas, who was a gift from her favorite brother Destruction. It's a matter of opinion which one keeps the other as a pet.