Rivera is a tall and flexible monster that works at Monsters, Inc. as a scarer. He is the second tallest scarer at Scare Floor F, tied with Joe Ranft and George Sanderson, and right behind Sulley. He is a slender orange monster with two eyes on small stalks, six long tentacles serving as arms and four shorter tentacles serving as legs. The tips of his limbs' skin are red and he also has green stripes around his legs. He also has a turquoise snake tongue. He is fifth on the Scarer's Leaderboard, and his assistant is Betty. He is only seen as a background monster and is not present at Harryhausen's, although the waiters are two purple recolors of him.
- Rivera has the exact same design as Tony, but without a fifth leg and a mustache.
- Rivera is named after Monsters, Inc. art department manager Jonas Rivera.