20Randall Boggs - Monsters Inc.
There's sneaky, and then there's Randall Boggs. One of the main antagonists in Monsters Inc., he's a chameleon-like creature with a serious case of jealousy when it comes to those who outperform him. Sure, it had to be hard to live in Sully's shadow and watch him dominate the rankings on
the Scare Floor. That was no reason to create a device that could actually harm children, though. That's really low.
Some villains are driven to evil after a single, life-changing event, but Randall Boggs' turn toward maniacal was years in the making. We learned in Monsters University that Randall always had a villainous streak -- and that his jealousy of Sully and his friends had been in the works since their fraternity days. That doesn't excuse his lack of scruples, but it does make him one of the more fascinating villains that Disney and Pixar have ever concocted.