What's the point of the new shirt? [OoT 38]

I don't really get it. I haven't really watched a whole lot of Game Grumps in a little while, so maybe this is a reference to a previous episode, but I haven't really seen anybody talking about it. Is it just the logo for the rap group "Run DMC" but with "DBZ" instead? Is it a reference to a previous episode, or is it doing a joke like Modern Simpsons does where they just change one or two letters of something popular and call it parody, or is it crossing over two things that have nothing to do with each other?

Color me completely confused. I don't get it. Even from a non-sequitur point of view, I still don't get it.