Looking for someone to voice a big black cat!

It's for a short sort of joke/gag. The animated short has already been done - But now we need a voice for the cat!! 

We are looking for comical voices - Think of him as a big silly harmless cat, who just stares a lot. 

We are more inclined for a British accent, any regional accents are welcomes, or RP. 

But we are open to American/Canadian accents too.