'Hah hah, I am pure, Thorn. I don't have the worries of life and love attached to me. I am the strongest now, Thorn. You don't even come close.' -Nega-Thorn, Series II, Chapter 66

Appears in: Series II, Chapter 60, Chapter 66

A representation of everything bad about Thorn. This includes his anger and his occasional insanity. A battle between Nega-Thorn and Posi-Thorn resulted in Nega being destroyed. Nega-Thorn's death lead to Thorn losing many of the dark powers he gained from Lucifer.