Rogu is a homunculus that formed from Roger's tumor in "Persona Assistant".
Irritated with Stan's complaints that his personas are pointless, he takes a trip to a hot spring and leaves Stan in charge to prove that his personas actually matter.Finding things in chaos on his return, he is shocked to discover that Stan went out dressed as Ricky Spanish on the advice of Klaus in order to straighten things out. As Ricky, Stan goes completely power mad and takes over the entire town, forcing Roger to bring out the only persona powerful enough to meet him toe-to-toe...wedding planner Jeannie Gold who also is Ricky's sister. As they clash, Roger is still almost defeated by Stan until Rogu, also dressed as Ricky Spanish slices Stan's throat. However, this is just the inner lining of the Roger suit, which Roger quickly peels off of Stan, returning his personality to normal. During another happy hour, Roger pledges to spend more time with Stan, and in order to facilitate that, his species had developed homunculus like Roku a stand-in doubles as Rogu is shown quarterbacking a football team.
Rogu attends Tuttle's eclipse party in "Stan & Francine & Connie & Ted" and helps Roger with Steve's arm in "Shark?!".