Erik Thiessen was a student at Leonardo High School along with Hawk, Croc, Dane, John Vautour, Craig Aucoin, and Beth. During high school, Erik dated the cute-as-a-button Wendy Greenspring. Erik is a fan of comic books, with his favorite characters being the ones who were the most popular in the mid-1990s. He dressed up as Gambit for Halloween 1997, and convinced Wendy to dress up as Rogue. As is evidenced by his t-shirt, Erik's absolute favorite comic book is Todd McFarlane's Spawn.
Once during phys ed class, Erik was ordered by Coach Carnage to do infinity push-ups with Biff J. Rockenheimen on his back.