The antimatter Chipmunks' existence depends entirely on Simon's invention, the Particle Accelerator, who won't allow for the Chipmunks to just walk on in and pull the plug. If even barely touched they'll be neutralised, as Simon's example goes, if one were to touch Theodore, Theodore would have never existed, every trace that he ever existed would have suddenly vanished and Dave would only have ever had two sons. They are destroyed when Theodore pulls the plug on the invention, causing the antimatter Chipmunks to glitch and disappear into thin air.
The antimatter Chipmunks appear to have nearly the exact same looks as The Chipmunks, only with some differences: their facial features are completely blank save for large, glowing green eyes. Their bodies are mostly transparent, but still have object permanence as they're shown to react to the ping pong balls being shot at them and can climb up things like the legs of a table with zero problems.
Much like Calvin and the Hip Munks, the antimatter Chipmunks also share an unfriendly attitude towards The Chipmunks.
- Their names are never mentioned.
- They don't speak actual words, but rather they produce a roar-like sound instead.