About the worst I can think of is pretty darned tame compared to lots of what I've read here.
We once fed a buddy a gadwall and a teal but told him it was a sharptail grouse and a hungarian partridge. He was unimpressed with our cooking skills.
Not really a prank, but still funny/cute. Dad packed up one of the younger nephews for an afternoon of deer hunting. Kid was 8-9. Dad had killed a deer in the AM, gutted it and left it in the snow to cool. Dad and the nephew were driving along and dad stopped and said, "Well, let's just take that one home." and loaded up the deer like that's how it was done, just find a dead deer with no guts and load them up.
Lots of good-natured ribbing but no other real practical jokes. Grandma's house is the closest thing we have to "deer camp" and grandma doesn't allow any sort of alcohol in the house so things stay mighty tame.
