Harry Dunne

Harry shows up late to a dog show with the dogs covered in food and loses his job. He takes little notice when his parakeet is found headless. He sets off with Lloyd for Aspen in the dog-shaped van. When they find Mary, he lies to his friend to go out with her. In the end an FBI agent had equipped Harry with a vest and a gun.

In the prequel, in 1986, Harry finally gets to attend a regular school. On the way he bumps into Lloyd and they become best friends. They fight over a school reporter, fall out, and make up once they realize they are nothing without each other.

Harry needs a kidney transplant and learns he was adopted, so his parents cannot donate. His piled-up mail includes a 1991 postcard from an ex-girlfriend, Fraida, saying she was pregnant. He goes looking for the daughter, Fanny, who was given up for adoption, hoping she is a match.

Jeff Daniels earned about $50,000 on the first film, and the studio did not want a dramatic actor in the role. His comedy career took off afterwards, according to Wikipedia.