The Troodon were carnivorous dinosaurs that lived in the Cretaceous Period, and who appeared as antagonists in The Magic School Bus episode, The Busasaurus.
Plot[]
When Ms. Frizzle, Liz and the class encounter a herd of Triceratops on a field, the pack of Troodon suddenly show up. They first appeared when they started chasing after a baby Triceratops to eat it. But just before the Troodon could eat the baby Triceratops, the big ones get in their way and protect their babies from getting eaten.
However, the Troodon then spot the kids and start to chase after them to eat them instead. Before the Troodon could eat the kids, Ms. Frizzle gives them Tricera-Shields to use to protect themselves. When using them, they watch so see what the Troodon are up to. Carlos thinks their deciding which one of them they should eat first, but Tim doubts it and tells Carlos it really looks like they want an easy lunch without a fight.
The Troodon then got scared by the horns on the Tricera-Shields and ran off. Wanda realizes the horns are what scared them away as the Troodon were afraid of getting hurt.