Prehistoric Woodchuck

If a woodchuck was ever able to chuck wood, the wood would either have to be very small, or the woodchuck very big.

And since we have every other kind of giant prehistoric creature (such as the sloth from here in Seattle), there must have also been a giant woodchuck. And a giant woodchuck would chuck wood like a mad chuck!

But it wouldn't need to, it would be giant and just chase you down and maul you up.