| Smilin' Joe Fission|
|Occupation||Film Strip Commentator|
|First Appearance||Homer's Odyssey|
|Voiced By||Harry Shearer|
Smilin' Joe Fission is the official mascot of the Springfield Nuclear Power Plant and the Springfield Isotopes. He also stars in filmstrips shown to visitors at the Power Plant, like the filmstrip the plant shows Bart's class. He looks similar to The Happy Little Elves. Since the episode Replaceable You, he has not been seen or heard of.