Rexxon was a robotic snake-like mutated monster that lay in the Toxic Caves of the Veg-O-Fortress. When Sonic the Hedgehog attempted to destroy the Veg-O-Fortress and Dr. Robotnik's robot operations, Rexxon grabbed Sonic by the fur when he entered the fortress, and took him to the level boss, Scorpius. Scorpius and Rexxon were quickly beaten by Sonic, though. (StH: #6)
- Rexxon is named after the gas station, Exxon, considering that he was slithering in oil.
- Rexxon is based on the mechanical sea serpent found in the first level of Sonic Spinball, Toxic Caves.