Dr. Doomis appears first during season 3 in the episode, "Smokin With Cigarettes". The psychologist of Lamilton Taeshawn, Riley's sociopathic, destructive friend, Doomis first took notice of Lamilton's behavior when Lamilton was still in kindergarten and convinced his grandmother to bring him in for questioning. He greatly believes that Lamilton is beyond a bad egg and is something demonic, due to his personality and anger. Unable to lock Lamilton away as he wishes, he instead secretly follows him in order to collect enough evidence to put him in jail. His obsession with Lamilton drives Lamilton's grandmother to file a restraining order against the doctor.
He was first shown interviewing Lamilton and asking him of what he liked to do. Lamilton explained that he liked doing bad things and smoking with cigarettes, which Doomis responded by telling him that his actions could hurt people and that smoking is unhealthy. He spied on Taeshawn and Riley, who were intruding Mrs. Von Heusen's house. He witnessed Lamilton who mercilessly shot her dog who was chained at the time. He turned Lamilton in to the police and Lamiton was sent to the system. The next morning, he met Riley and introduced himself and revealed himself to be the one who called the police on Lamilton. Riley panicked at first, but Dr. Doomis stated that they'll never let him out, as he would be locked up forever, or so he thought. Lamilton was let out of the system early as they didn't have enough proof. He phoned the Freeman's home to warn Huey and Robert, and told them not to let out Riley out of the house for his safety. Robert replied that Riley was in detention. Dr. Doomis ordered Huey and Robert to get there immediately with anything to put Lamilton down for good, and claimed that they had no idea what they were dealing with. They later got to the schoold and Riley and Lamilton at the nick of time. Lamilton was hanging on the school building and was this close to dropping. Doomis saw this as a great opportunity to kill Lamilton. He pulled Riley's hand from Taeshwan's and the young boy dropped to the ground, believed to be dead. Riley was shocked with Dr. Doomis' act, but Doomis believed that the boy deserved to die after what he done.
Everything is calm at first until Robert gasps as he notices that Lamilton's body gone as if something took him away, but realises that he's just limping away. The psychologist cannot believe this and actually jumps off the building only to land on the boy just to kill him.
His ultimate goal is to kill Lamilton Taeshawn, believing him to be purely evil, and that his existence will endanger humanity. He even goes so far as to jump off a balcony in an effort to crush Lamilton.
- He is a parody of Dr. Loomis from the Halloween film series.
- Tom Kane once provided the voice of Dr. Loomis in the 1998 film Halloween H20: 20 Years Later.