Rayvenous is a kaiju from the film series that began with Attack of Humungado. He takes the form of a giant malevolent manta ray which can fly, with the ability to emit a freezing beam of energy from his mouth. Flashing a bright light in his eyes makes him go right to sleep. In the second sequel, he and Humungado teamed up to fight Supersaurus and Rhinoctopus.
During a showing of Attack of Humungado, the high-tech projector malfunctioned, creating an instance of Rayvenous in the real world. The creature flew off, and the next morning he attacked the Mayor's mansion. When the rescue team turned up, Rayvenous went underground, and they eventually caught up with him in the cave system, using his weakness to light to capture him. Securely locked in a tank, Rayvenous was returned to the drive through to be returned to the movie however a mishap resulted in Humungado also being manifested in reality. Rayvenous briefly escaped while the rescue team were busy trying to corral Humungado, but Doc Greene and Frankie used a flash of light to return him to his tank, and he was subsequently used as bait to draw Humungado back to the drive in. While Doc Greene was preparing to return the two Kaiju to the movie, Humungado formed an alliance with Rayvenous to team up against the Rescue Dinos. Blades pounced on Rayvenous, causing him to crash into the other Kaiju shortly before Doc Greene could finally complete the process, returning the pair to the film.