Harold Smith is a minor villain from The Powerpuff Girls. He appears in the episode "Supper Villain" and its sequel "Just Desserts".
Harold was the girls' next-door neighbor. He lives with his wife Mary Ann Smith and his children Bud and Julie. He is an average suburban factory worker who produces mustard jars. However, he has a darker side. He does not like the Powerpuff Girls and over a period of a few days secretly builds a villainous device, complete with a costume, in his hopes to get rid of them.
In "Supper Villain", the girls are invited to the Smiths' house for dinner. Mary Ann tells Harold to not ruin this dinner. The girls talk about their rescue of the Mayor from Mojo Jojo. When Blossom says that there is no villain who can stop them, Harold comes out in his badly-made villain costume saying "Oh, really?" and tells of his plan to melt the Professor's head with an altered hair dryer.
At dinner, the girls keep an eye on Harold, who is waiting for the right moment to melt the Professor's head. After dinner, Mary Ann serves everyone coconut cream pie for dessert. Blossom throws a pie at Harold. Harold throws one at the Professor, but hits Mary Ann instead. Everyone starts throwing pies until the police come in. The girls and the Professor point out that Harold has a gun, and Harold is sent to jail.
In "Just Desserts", Harold gets out of jail and returns home to find that Mary Ann is planning to destroy the Powerpuff Girls. Harold agrees to this, and their kids join in as well. Everyone changes into their villain costumes, and Mary Ann reveals her changes to the family car. She and Harold plan to wreck the Powerpuff Girls' home - which they do.
Later, Harold drives the car into the girls' house and starts a chase around. The girls destroy the car. Mary Ann reveals why she is trying to destroy them, and the girls beat the family up. Harold, Mary Ann, Bud, and Julie are all sent to jail.