He was voiced by Michael Gough, who also played Gnasty Gnorc in the Spyro the Dragon franchise, Lord Osmund Saddler in Resident Evil 4, the Dragon in Disney's Timon & Pumbaa, Lord Hertford in the 1996 animated version of The Prince and the Pauper, Tim Scam in Totally Spies, and Samuel in Disney's Tarzan.
Along with his fellow agents, Smithson was involved in Benedict's plot to steal a tractor beam from a U.S. military base so that they can use it to move the Moon into creating a new Ice Age to raise test scores. Following the Legion's takeover of Third Street Elementary (as it was closed for summer vacation), Benedict assigned his agents to act as guards, and Smithson was tasked as a lookout alongside Henderson, Underville, Franklin, Morrisey, and Goodman in front of the school.
Following the capture of Principal Peter Prickly and T.J. Detweiller when they investigated of what's going on, T.J.'s friends decide to take action by gather all of the students and teachers to help reclaim the school and defeat Benedict. As part of the plan, Mikey stands behind and on top of a bush singing, diverting the attention of Smithson and the other guards. Annoyed by this, Smithson and the guards tried to get rid of Mikey, but they fall into a huge dug pit created by the Digger Twins using space shovels.
He was eventually arrested and sent to prison alongside Benedict and his other men after their plot was foiled.