Back in high school, Chet constantly torments Stanley for fun by giving him wedgies, except he calls them "melvins" and putting his head in a toilet, (flushing him). His last act of torment on Stanley was the "Stanley Doorstop" wood shop act where he mercilessly glued wood into Stanley's skull as his wood shop term project. Chet was later expelled from school for his stunt and met Stanley again as an adult when he was hired as the new bank employee, despite Stanley's horror.
Chet's bullying was apparently a deep rooted psychological problem as he made a call to his therapist upon meeting Stanley again after the first time in years and said he had a powerful urge to "flush him." But tries to control his urges.
Chet got the other half of the Mask when he got it from Walter after he kicked him when insulting him. When putting it open, it turned half of him into a ruthless, bullying murderous monster and plans to get revenge on Stanley for getting him expelled back in high school and continue tormenting him like he did. Chet encountered Stanley, (Who's also wearing his Mask-half), at Edge City High School for a fight. The two dueled with each other with their Mask-half powers and tricks until they chased into their old wood shop classroom and Chet's Mask persona tries to kill Stanley.
After wearing the mask for a short time he really got a good look at himself claiming he 'looked right into the darkness' and saw how he used to be when his Mask-half tries to kill Stanley/The Mask by sawing him in half, implying he was finally cured of his urge to bully. He later reconciles with Stanley by apologizing to him for everything he has done to him and vows to leave Edge City to find a new future, before being fired by Charlie (still wearing his chicken suit given by Stanley/Mask) for attacking him and leaving him naked back at the Coco Bongo.
A massive exaggeration of his now repressed bullying self. Chet's mask-self was more than willing to kill people for the sheer enjoyment of it much to his non masked half's horror. This could be a reference to the original Big-Head and Stanley Ipkiss from the comics: a joking red-suit Killer with no mercy, making him the animated version of Big Head.
- Chet Bozzack was voiced by Dan Castellaneta, who is best known for voicing Homer Simpson, Grandpa Simpson, Krusty the Klown and various characters from The Simpsons TV series.
- Chet's facial appearance and smile somewhat resembles Alfred E. Newman, the mascot of Mad Magazine.