Oh Brother Where Art Thou is an episode of the ALVINNN!!! and The Chipmunks series.
When Simon goes missing and nobody seems to remember who he is, Alvin worries that he is losing his mind.
Simon is working on his science fair project when Alvin urges Simon to go to the water park "Thunder Waves," claiming it's related to his science project. Simon states they can't go anyways because the room is a mess; Alvin, wanting to go, tries to sneak out via the tree, but hurriedly climbs back into their room when Simon, who is fixing the toaster, sees him. That night, Dave tries to talk to Alvin about leaving his golf club outside, but Alvin, too hasty, calls Simon a snitch, thinking Simon told Dave about him sneaking to the water park, hurting the blue-clad chipmunk. The next day Alvin gets his wish when he finds Theodore playing with Simon's robot before denying the existence of Simon and explaining that he and Alvin flunked out of school. Alvin, determined to solve the mystery of Simon's disappearance, discovers that the toaster is still not fixed, cannot find Simon in his contacts list, and Simon's bed and clothes have disappeared. After thinking that the power of his mind caused Simon to disappear, Alvin runs to ask Miss Croner about Simon, who only knows about her cat named Simon, while The Chipettes think that Simon's Alvin's imaginary brother. The girls inform him that he's not in a band because he doesn't have enough voices. He begins to think that they think he's crazy and he rushes off before he could be pull in a straight jacket or given anti-crazy pills. Alvin, desperate to have Simon back now, suddenly believes he willed his brother back into existence before discovering that Theodore and The Chipettes were teaching him a lesson of the importance of Simon in Alvin's life. Simon and Dave actually just went to get tickets to the water park he was dying to go to.
- Goof: In one scene, Simon is missing his tail for a few frames.
- The same goof happens to Alvin during the scene where he is pretending to be asleep.
- Alvin makes references to both Star Wars and Star Trek II: The Wrath of Khan when playing with a red lightsaber toy and refering to himself as Khan.
- A miniature-sized version of Harmony appears in this episode.
- Talking Teddy makes another re-appearance in this episode.
- The flyer for the water park that Alvin holds up shows that the park is titled as Aqua Plus, to which is a real place in Crete, Greece, though spelt slightly differently (Acqua Plus).
- Thunder Waves and The Dead Zone Drop are likely names of the park's attractions.
- Depending on continuity, this could be the name of the water park that's seen in The Crow That Ate My Homework.
- When this episode premiered in the US, it aired with a re-run of Ballet Boys.