Stinging Glow Urchins

The Stinging Glow Urchins are sea urchins used in the Toxicity Challenge in Monsters University. The urchins are dark blue, but glow a bright purplish-red off and on. They are highly toxic, and anyone stung by them will massively swell up as if they were a balloon. According to Claire Wheeler and Brock Pearson, the urchins represent human belongings in the game, as actual human objects are supposedly too toxic to be used.

Monsters University
In the first event of the Scare Games, the Toxicity Challenge, monsters from the biology class would scatter the urchins through the sewers. The six teams will have to traverse the sewers without touching the urchins, and the last team to reach the finish line will be kicked out of the Games. Unfortunately, Mike Wazowski and James P. Sullivan of Oozma Kappa took this as a new stage for their arguments and competed against each other, resulting in the other members of their team to be left behind and team OK to come in last. Fortunately, team Jaws Theta Chi was disqualified instead as they were all caught cheating by using an illegal protective gel, allowing the OKs to keep participating.