Harold typically wears a striped shirt and beige baggy pants.
Harold is a worrywart type of fellow; he's very overcautious and neurotic. He is usually happy-go-lucky and is always seen as being very cheery. But on the flip-side, he tends to be extremely fussy about any possible source of danger. Harold, in some episodes, is sometimes a few coconuts short of a palm tree, and easily snaps at other people when angered. He also has an unhealthy love for his car, which he calls "Monique" and is also indeed very clumsy, as revealed in "Father From the Truth".
He is obsessed with his wife's homemade cookies as shown in "Crumbs!". His love of them is so great he is willing to chop down a tree Kick is hiding them in and dress up as his wife and Gunther to fool Kick. His hunger for them is so notorious that no one in the neighbourhood is willing to help Kick come between Harold and the cookies. Once the cookies are gone he will snap back to normal within seconds.
He seems to have a strong relationship with Kick as they're seen laughing at some of Brad's misfortunes.