I don't want to be hyperbolic but that's the dumbest shirt I've ever seen. 

There's a type of comedy out there that's called anti-comedy. Think of Andy Kauffman or Norm MacDonald. Guys that are funny by not being funny. It's a tough line to walk and can get REALLY not funny really fast. I like that kind of humor. It's not for everyone but I like it.

I think they're going for that in this t-shirt but I'm not really sure. This isn't a pun or even an obscure inside joke. They're just putting two things together that don't match. It's not even clever.

They also have one for our neighbors north of the border that also makes no sense.

Birdfur

I wouldn't want to wear this shirt just because of the comments you'd get from everyone being confused by it. What's your response? It's supposed to not make sense? I don't know. Maybe I'm just a grumpy old guy.

If you're actually interested in this shirt or some of their other equally absurd ones you can head over to their website.