Nick O' Teen is a tobacco additive and the main antagonist in the Ozzy & Drix episode, Where There's Smoke.
Nick entered Hector's body when Hector smoked a cigarette after being pressured to do so. He entered with his henchmen: Butane, Carbon Monoxide, and Tar. He plans to brainwash the cells in Hector with his smoke to have them follow his command so he can access the brain to get Hector to take up smoking. The more cells he controls, the more powerful he becomes.
While disguised as the lead singer of the band Metabolica, he managed to brainwash Mayor Spryman as well in the Air Fair. Nick became powerful enough to get to the pleasure center of Hector's brain and alter smoking as what he would want. However, Hector chose to quit smoking on his own in favor of Christine, his crush. Nick was weakened by Hector breaking the addiction, and he was shrunk down. Ozzy then squash him under his shoe.
- He was voiced by Tim Curry, who was also the voice of Scarlet Fever in the Pilot episode, Home With Hector.