jackopotamus 

Short and to the point, a fat man who jacks off, or a fat man that hasn't been laid and has no other choice.

"Looky here a jackopotamus, poor bastard."

jackopotamus by Ashmarie November 30, 2006

Hackopotamus 

A creature who refuses to improve an existing skill set.

Did you see that guy's work? What a hackopotamus!

Hackopotamus by ChrisN_PGH March 5, 2011

Jankopotomus 

A relitively large faggot that's all jankin all over the place all the time.

Guy 1: Man your brother is a huge Jankopotomus sometimes dude

Guy 2: Dude i know. Jankiest Jankopotomus i know.

Jankopotomus by TastyCereal April 10, 2011