marmota monax = woodchuck.
http://en.wikipedia.org/wiki/Groundhog
As stated above - it is a juvenile. Older ones get white around their snout. They can wipe out a garden pretty quick.
.22 HP short should do it.
Very fatty meat and gamey. I rather eat beaver!
Muskrats aren't bad either, but tree rats are tastier. Sewer brains ...... LOL. I got ya on that one, huh?! :P