The Swamp Thing returns to battle the evil Dr. Arcane, who has a new science lab full of creatures transformed by genetic mutation, and chooses Heather Locklear as his new object of affection.
| Actor | Role |
|---|---|
 Louis JourdanDr. Anton Arcane | Dr. Anton Arcane |
 Heather LocklearAbby Arcane | Abby Arcane |
 Sarah DouglasDr. Lana Zurrell | Dr. Lana Zurrell |
 Dick DurockSwamp Thing | Swamp Thing |
 Joey SagalGunn | Gunn |
 Ace MaskDr. Rochelle | Dr. Rochelle |
 Monique GabrielleMiss Poinsettia | Miss Poinsettia |
 RonReaco LeeOmar | Omar |
 Daniel Emery TaylorDarryl Hallenbeck | Darryl Hallenbeck |
| RRalph PaceSheriff Beaumont | Sheriff Beaumont |
 Alex VanGurdell | Gurdell |
 Christopher DoyleLeechman | Leechman |
| RRex PiersonDr. Rochelle Mutation | Dr. Rochelle Mutation |
 Tony SearsHarry Dugan | Harry Dugan |
 Bill EudalyWithered Chuck | Withered Chuck |
| AAnthony CecereConkilin | Conkilin |
| TTimothy BirchClyde | Clyde |
 J. Don FergusonBob | Bob |
 Jim GrimshawMorty | Morty |
| AAlbert B. Cooper IVTaxi Driver | Taxi Driver |