Grouchopotamus 

A man who becomes grouchy with little to no warning, most often observed in the early mornings.

Liz: "Hey Chris wanna go work out?"

Chris: "I don't like these kind of suggestions so early in the morning."

Liz: "Why do you have to be such a grouchopotamus? Besides, it's like noon."

Grouchopotamus by Chriz10 June 13, 2011

grouchapottamus 

A really grouchy/angry/moody person

Tomm:Oh no here comes rachael...
Scott: AARRRGGGHHH THE GROUCHAPOTTAMUS!

grouchapottamus by TOMM-BOLO August 27, 2008