As might be expected of a ghost who considers teen comedy movies to be art, Wendel intends to have some fun with his newfound intangibility.
Wendel is a spook. In life, he was a nerdy class clown of a college student who died in a dangerous hazing stunt while trying to join the Alpha Tau fraternity. Although his friends Gary Hall, Wyatt Mitchell-Smith, and Chett Paxton are holding a séance for him, Wendel's spirit is trapped in a pair of novelty chattering teeth, where he seeks revenge against Ted Gable, the head of the frat.
Wendel is unlocked in Weird Séance. To free him, Ted Gable needs to be scared away from the house. Since causing everyone in the house to flee is the goal of the mission it's almost impossible for Wendel to not be unlocked. If Ted gets scared away last however the mission will end before the unlocking cutscene initiates, forcing you to play the level again if you want to unlock Wendel.