This series only ran for 5 episodes (including a pilot) but spawned a successful line of figurines based on Swamp Thing and the Un-Men, and a video game for the NES and Gameboy. As in the films, Arcane is responsible for Alec Holland’s transformation into Swamp Thing and Abby is his stepdaughter.

Cast:
Len Carlson as the voice of Swamp Thing
Don Francks as the voice of Dr. Anton Arcane
Tabitha St. Germain as the voice of Abby

Summary:
Swamp Thing protects the swamp from Arcane and his gang of genetic mutants, the Un-Men.

Release:

Swamp Thing : Guardian Of The Earth DVD (88 min.), UAVCO, 2004. Region 1, NTSC (USA/CA). Collects all 5 episodes. Now out of print.

Swamp Thing : Guardian Of The Earth DVD (88 min.), Anchor Bay, 2008. Region 2, PAL. Collects all 5 episodes. EAN: 5060020700095

Further Links:
IMDb – full cast and production details.
CultTVman’s Swamp Thing Page focuses mostly on the live-action series, but provides a bit of information about the cartoon, and images of the related line of toys.