Here's the audio of Danny DeVito saying, "What the F*ck is Pokemon?," from the An Evening with It’s Always Sunny in Philadelphia at the
LA Paley Center, which have some really great events for fans.
Sorry if ain't the best audio quality, but I was only planning on doing a write-up and never knew something so magical would be said.
I believe, I heard Hulu, sponsor of the Paley center, would have video of the panel through their services, so you might be able to find Danny saying it there too.