Ultimate Spider-man: Season 4, Episode 5

4 - 5: Lizards

After Spider-Man and the Web Warriors are told by Vulture that there is a spy among the other heroes, he and the Web Warriors work to find out who it is while Nova and Nick Fury are away on a secret mission. They test out the new training area that was designed by Leo Fitz and Jemma Simmons, only to discover that the robots were sabotaged. Dr. Connors once again becomes Lizard and now sports a contagious bite that turns others into lizards. When everyone ends up infected, it's up to Spider-Man to stop the Lizard and cure everyone before the infection spreads out of the Triskelion. In the end, Rhino is revealed to be the spy as he and Doctor Octopus escape with Agent Venom as their prisoner.