1. Someone who scats while having sex. Scat used here means a fast rapping of meaningless words
2. Someone who has sex with the Debbie willingly. Called a Scatman because the only known person to ever have had sex with the Debbie was a scatman.
1. Me: Dude, I think your parents are having sex and one of them's scatting!
You: Yeah I know, my dad's a scatman
-Then we hear "scatabaddabeddabettadebado I'M THE SCATMAN"-
Me: You need to ask him to stop doing that, it's creepy
2. Somehow, Pete turned out to be a Scatman. I feel bad for anyone who has ever been friends with him