Diente was a human dentist who served as the assistant to the Tooth Fairy. However, upon hearing that Haley Long (a girl who can turn into a dragon) was about to lose her first tooth, he turned against his boss and took possession of her wand and her Tooth Minions. He planned to steal Haley's tooth as dragon teeth have mystical powers.
However, upon reaching the Long house, Diente discovered that it had a magical forcefield, preventing him and his Tooth Minions from going inside. So Diente waits outside to make his move.
Meanwhile, the Tooth Fairy (after barely escaping being crushed by a car compactor) arrives at Grandpa Lao Shi and Fu Dog's door and explains Diente's plan and Fu and Grandpa realize that Haley's in danger.
When Jake and his friends take Haley to the concert, Dr. Diente makes his move and kidnaps Haley. Jake, Grandpa, and the Tooth Fairy arrive to the rescue and in the ensuing battle, Haley's tooth flies out and lands in Diente's hand. Diente takes it and wraps his hand around it and places his hand into a pot of soil, causing the tooth's powers to activate and turn Diente into a giant white-furred monster.
Diente then goes on a rampage in New York and starts to steal the money the Tooth Fairy gave to children. Luckily, Jake was able to stop Diente with his dragon powers by taking a billboard-sized TV and smashing it on top of him, electrocuting and destroying him for good and leaving only his shattered glasses on the street.
"You break into houses and leave money?! THAT'S NOT A VERY GOOD BUSINESS MODEL, IS IT?!"
"Good? Who said anything about good?!"
"Do you know how long I've been biding my time sneaking teeth from your stash to build my army of Tooth Minions, watching you giving away millions of dimes, quarters, dollars to ungrateful, grimy little brats night after night?!"
Diente discovers that the Long house is protected by a forcefield, preventing him and his Tooth Minions from going inside.
"That little girl has to come out sooner or later. And when she does... (laughs evilly) ...we'll make our move.
"Actually, the Tooth Fairy won't be leaving "cha-ching" for anyone."
"I'm a different kind of dentist. The kind who's gonna be getting back every penny that fool Tooth Fairy gave away!"
"As soon as I plant your precious Dragon Tooth, I'll be unstoppable!"
Dr. Diente shocked.
"Tooth Minions, attack!"
Haley's tooth flies out of her mouth and Diente catches it.
"Who needs a wand wen you've got the tooth of a dragon?!"
"At last, the legend of the Dragon Tooth will be the stuff of legends no more!"
Diente transforming into a giant white-furred monster.
"Now, if you'll excuse me, I'm off to recoup some of your idiotic losses, fairy!"
"Just in case I need a few extra dragon teeth, come here, you!"