Ozzy & Drix is an animated spin-off TV series based off the 2001 feature film "Osmosis Jones" that was produced by Warner Bros. Animation from September 2002 to July 2004.
Taking place after the film, the titular characters, Osmosis Jones and Drix, find their way out of Frank's body and instead inhabit and protect the body of a young teenager named Hector, all at the anthropomorphized cellular structure of his body. In contrast to the film, which combined live-action with animation, the series is strictly animated with none of the voice actors from the film reprising their roles.
The Conqueror Worm (S02E17)
A Growing Cell (S02E21)
As Hector develops unhealthy eating habits, he begins to put on weight as well as expanding his fat cells. Namely: a young one that is kidnapped by Stickety Lipid in a plot to increase Hector's cholesterol.