He is more than just a nerd, he is an ultra nerd. From his inch thick glasses, to his powder blue suit, his whole image just screams "nerd". He has a very odd haircut that looks like it was mashed down on one side. He also has a ton of allergies (and is on many different prescription drugs).

Most of Arnold's scenes are visual comedy (he doesn't talk much). An example of this would be when he was trying to paint a post, but he was standing so far back that he couldn't see it.