Bowser

Bowser is the biological father of Junior. He acts normal at most times, but sometimes, such as in The Teacher Prank, The End, Science Teacher, and Missing Homework!, he can be as stupid as a rock.

Personality
Bowser can be a dick sometimes, usually in the School Shenanigan Days series.

In The Teacher Prank, Bowser makes Junior go to school on a Saturday, when clearly, you don't go to school on a saturday.

In The End, he forces Junior to get pudding for him, and BLAMES his own son for the pudding being expired, so he spanks him to death.