Jimmy puts on a slightly horrendous Swiss accent and says things like this:
"I'm playing the tennis so perfect, I'm the best and all the other players they just don't want to play me they get afraid to play me, they get humiliated because I play so good and at the end of the match they can't even look their own father in the eye."
And when speaking about Nadal he says this:
"On the court I want to kill him. I want to destroy him, like the angry birds, I want to slingshot myself into his little fort and eat a pig with a hard helmet on, and the ceiling falls in on him, suffocates him and kills him, and I get the 500 points, and then game, set, match."
It's pretty funny, and definitely worth taking a look at. You can see the video here.