Not-So-Harmless Villain: Harry actually manages to get information from the neighbors by disguising himself as a policeman.
At the end of the first film, he outsmarted Kevin and caught him. He would have bitten Kevin's fingers off if Marley hadn't shown up. At the end of the second film, he pulls a gun on Kevin and is about to shoot him in the face when the pigeon lady appears.
Took a Level in Dumbass: In Home Alone 2 he is a lot dumber than in the first film, possibly thanks to the head injuries he sustained in the first film (and/or additional head injuries he might have sustained in prison).
Karma Houdini: In the second movie. Sure, Kevin pushes him down after the electric candle debacle, but Buzz still gets away with conning the whole family with an insincere apology after the fact, and suffers no retribution.
Pet the Dog: Although he does redeem himself with a genuinely sincere speech in thanks to Kevin at the end of the sequel.