Ed (Teen Titans Go!)
That's a deduction.
~ Ed to Robin

Ed is a burglar and the main antagonist of the Teen Titans Go episode "Driver's Ed" and a minor antagonist in the previous episode "Pie Bros" and later a supporting antagonist in the episode "Caged Tiger". He tricked Robin into thinking he was a driving instructor when in reality he was using Robin as his getaway driver. After Robin takes him on an insane ride, he gives Robin an A and tells him he was using him the whole time. Robin claims he knew that and that was the reason he didn't warn him a demon. Suddenly, a demon pops out of nowhere and drags Ed into an alternate dimension. It's unknown if Ed survived or not.