First off, the Pope looks evil enough so I would change his face much. I would give him some really long nose hairs and a pair of "nerd" glasses though. I'd change the color of his teeth from yellow to white and instead of a cross he'd have a weed leaf around his neck.
He'd be grabbing a boob in his left hand and high fiving some little kid with his right. Instead of that blurry background I'd have him look like he was the lead singer of White Snake.
I'd make it look like a waterfall was pouring from his ears and flowing into a dog bowl. There'd be this little cowboy on a dog and with a freaked out look on his face because the dog is wild and it's going to drink the waterfall water. "Whoa! Little Doggie!" he'd be thinking (you couldn't see that but you'd know).
Instead of white hair he's have bird crap and there'd be a bird in the background sitting on the drummers shoulder smoking a cigarette.
Massive amounts of chest hair would be billowing out of his mouth.
Steam would be pouring from his ears and the top of his head would be popped off like a small nuclear explosion just took place.
He'd be wearing a Superman cape.
He'd have his grocery list penned on the palm of his hand.