Dabney Hooper, played by Kyle Sullivan, is one of Malcolm and Stevie's more emotionally-stricken and flamboyant Krelboyne classmates and best friend for the first four seasons of the show. He mentions to have a unnamed brother. Like other Krelboyne students, Dabney is regularly bullied and often suffers the consequences of schemes with which he helps Malcolm. Over the course of his appearances, Dabney displays vague homosexual traits, and often shows affection towards Malcolm. Dabney has an unhealthy relationship with his mother, Dorene, who orders her son around and attempts to dominate almost all aspects of his life. However, in "Hal's Friend", after Dabney receives a paintball gun as a birthday present from his grandfather, only for Dorene to take it away, Malcolm secretly takes him to a paintball battle course, and in the process he learns to stand up for himself and adopts a no-nonsense attitude towards his mother
Like Malcolm's other Krelboyne friends, Dabney appears less frequently during the show's fourth season, eventually leaving Stevie as Malcolm's only friend by Season 5. Interestingly, Dabney is a undergraduate house at Caltech, a university well known for its emphasis on the natural sciences and engineering.
It was shown that after an experiment gone wrong in Season 3's Cliques, the Krelboynes temporaily had to move into mainstream eduaction. In woodshop, Dabney fit right in with the jock clique after helping a jock get a splinter out of his finger. He soon became a leader of the jocks and there was about to be a school fight with the other cliques when Malcolm showed up to stop it.
Despite being implied to have homosexual feelings for Malcolm, he is also shown to have affections towards girls as well, it is likely that he is bisexual or that this is a cover up for his real sexuality.