Sinestro is a villain in DC Comics. A rogue member of the Green Lantern Corps, he often opposes Hal Jordan, the Green Lantern of Earth. Sinestro was a member of the Legion of Doom on Challenge of the Superfriends.
Sinestro was a former member of the Green Lantern Corps who was banished into the anti-matter universe of Qward. He acquired a power ring that emits yellow energy to counter Hal Jordan's green energy and became a member of the Legion of Doom.
- Sinestro (Super Friends) at the DC Comics Database Wiki