In FusionFall, he is found at Genius Grove, alongside Dee Dee and Numbuh Five by Dexter's old home in the past. Also please note the professor is nowhere to be found in the Future. Because Buttercup is his daughter, he is very sorrowful about nearly losing her after her last fight with Mojo before Fuse's arrival, but is very happy when the player tells him about what happened to her during the "I'm Still Standing" mission given by Buttercup at Marquee Row. He has a strong love and always makes sure his girls are all right (leading him to falsely identify Fusion Bubbles as the real Bubbles in a clouded battlefield). His Fusion is named Professor Plutonium and looks like an exact duplicate, except with a lab coat and tentacles coming out of his back. He is the only Fusion that has a name that doesn't begin with "Fusion." This has been changed so his name is now "Fusion Utonium."
In the manga, the professor seems unaware of Computress's secret crush on him as they deal with the Terrafuser. His Fusion counterpart, Professor Plutonium, has tendrils and is fought in the same Infected zone at the same level.
- Professor Utonium is one of a handful of characters to have a fusion that has additional features that the original character didn't. In his case, his fusion has tentacles that stick out of his back, and originally had the name Professor Plutonium