Impse

Impse is the act of copulating with an imp. The name is a play on goatse, a famous shock site.

Impse first appeared in a piece of fan fiction posted in the Doomworld Forums. An interactive WAD Imp Encounter was later created to follow the story. This helped to spread the joke more widely.

The Impse image also makes an appearance in Action DOOM and Massmouth 2.