Mantis Toboggan, M.D. was a pseudonym briefly used by Frank Reynolds to capitalize on the failed relationships of Dennis and Mac. The character surfaced again when Frank proclaims that he wants "seconds", and attempts to undermine Dennis' attempt to win back the heart of a woman who seemingly slipped through his "system". ("The D.E.N.N.I.S. System")
Reynolds once again assumed the moniker in a misguided attempt to make a "viral video" for Paddy's Pub to increase their web presence. Reynolds mistakenly thought the concept was a "virus video" centered around an actual virus, and used Toboggan as a central figure to proclaim that people who came to Paddy's would be "infected". ("The ANTI-Social Network")
- Frank: Dennis, I've been looking all over for you! Where ya been? (To Caylee) Hello. Dr. Toboggan. Nice to meet ya.
- Dennis: Frank, what the hell are you doing?
- Frank: Actually, it's Mantis. Mantis Toboggan, M.D. I got your test results! You're positive! You've got the HIV! Yes, AIDS, big time! You've got the AIDS, big time!