When a dragon wearing very large underwear threatens the kingdom the Knights of the Round Table run away, leaving Sir Percival's young assistant, Cole, to face the beast.
Blue Bison prides himself on always looking clean and neat, so when he goes for a haircut and discovers everyplace is closed, he is very upset, but his little sister Bubble Gum Bison and her utterly ridiculous idea saves the day.
After realizing that the Underwear Dragon misbehaves only because he cannot read, Sir Cole and his would-be assistant, Claire, are determined to help the fearsome beast.
Bubble Gum Bison tries to avoid taking a bath but ends up needing one after a messy adventure, only to discover there is no water due to her brother Blue Bison's accidental damage to the water tank.