Someone who digs up your yard; a dog who digs up your yard; a kid who digs up your yard; an x-boyfriend who digs up your yard with his 4 x 4 truck.
"That stupid mudmooser dog of mine dug up the yard again." "Look what my x-boyfriend did to the yard--he's such a mudmooser." "That mudmooser kid did this with his dirt bike, I am so going to lose my security deposit." "YOU MUDMOOSER! Stop digging holes in the yard!"