From what I got from Justin, my previous sketches of Lenny looks a little too conniving due to both his poses and the length of his muzzle. Often, when we see weasels with long muzzles, we think of these fellows:
Sleasy, villainous and up to no good. True, Lenny would have a hint of that in the "lovable jerk" type of personality, but I don't want him to turn into a character that you could ultimately dislike. Thus, I altered his design a tad.