A fur tumor is when an animal gets their fur so matted up and such, -caked with mud maybe- that it literally seems like its part of the animal...
Guy 1: Woah! Did you see the vet cut off Fluffys fur tumor?
Guy 2: Yeah, biggest fur ball I ever seen!
Guy 2: Yeah, biggest fur ball I ever seen!
by EmmaTheLeoaprd June 28, 2010
Get the Fur Tumormug.