Quite simply, a cross between a panda and a cow.
Guy 1: "Dude! that thing is whack! It looks like a panda and a cow made it! wtf is it???"
Guy 2: "dude, that's a panda cow!"
Combination of the two words JOCK and NERD to define someone who is not only extremely smart, but extremely sporty too.
You're a jock, but a nerd too, making you a jerk.