All I can remember is that he was a cartoon villain who was super old, in a wheelchair, had a huge forehead, with purple glasses, and had a white lab coat on. I'm pretty sure he was a doctor or evil scientist. It was an older cartoon shown on Cartoon Network I think. I used to watch it as a kid so around 1998-2004.
The photo is a fan art I found that looks very similar to him. The one I am talking about is much more cartoon-like.