I can't put my finger on it,but something about the muzzle or maybe the whole head appears to be slightly off a little. You did an excellent job on the body though and fixing the leg. ^^ I also love that you incorporated coyote body language into the mount by giving him an arch back to go along with his growling face expression.
That form is from McKenzie (CY-V5-OM) stalking, defensive pose. Nothing altered on him besides cutting out the mouth slot for the jawset. He has a 4-1/2" A-measurement but the form was actually shorter by an Inch on his actual length but it wasn't a problem with it being on the body end of it.