Dr. Slug is a very minor villain from Darkwing Duck. He is frequently mentioned in various episodes as being Public Enemy #1, as well as Darkwing's ultimate arch-nemesis and a fearsome criminal. However, he never ever appears in any episode, as his entire existence is used more as a running gag. The fact that he is Public Enemy #1 is often used by Darkwing Duck to mock NegaDuck, who is just Public Enemy #2.
His only appearance ever in the show is at the beginning of the episode "Inside Binkie's Brain", where he has cornered DW and Launchpad in an alley and is about to run over them with a saw, but DW simply shouts "STOP!", causing the scene to freeze, as DW felt was a good time to answer some fan letters.
- He bears a physical resemblance to the Seal Prince.