Tyrannosaurus Rex is a villain in Disney's 3rd feature-length animated film Fantasia. He serves as the main antagonist in the segment featuring The Rite of Spring by Igor Stravinsky.
The other dinosaurs are seen eating and drinking at a lake when the Tyrannosaurus Rex appears. The other dinosaurs express visible terror as they all attempt to flee, with the Tyrannosurus Rex giving chase and biting at passing Pteranodons and Triceratops. The Tyrannosaurus soon catches up to and confronts a lone Stegosaurus and attacks. It bites its tail, but the Stegosaurus shakes it off and turns to fight. As the other dinosaurs look on, the Tyrannosaurus bites the Stegosaurus's neck several times, with the Stegosaurus repeatedly using its spiked tail to hit the Tyrannosaurus off. Eventually, the Tyrannosaurus manages to bite down and break the Stegosaurus's neck, killing it. The Tyrannosaurus Rex then proceeds to eat the Stegosaurus as the other dinosaurs leave.
The Tyrannosaurus is later seen during a massive drought that gradually causes the extinction of the dinosaurs. The Tyrannosaurus collapses and dies in the dust next to many other dinosaurs.
Tyrannosaurus Rex is seen as The Disneyland train travels to the Primeval World diorama. In it, it is seen reenacting its battle from Fantasia.
In Walt Disney World's Epcot there is a ride known as Ellen's Energy Adventure staring Ellen DeGeneres and Bill Nye the Science Guy. Together they discover the history of fossil fuels. At a point in the ride, several dinosaurs are seen, the most notable being a Tyrannosaur fighting a Stegosaurus.
At Downtown Disney's T-Rex Cafe, there is a large Tyrannosaurus with its young.
The Tyrannosaurus (perhaps not the same one, but possible) has made other appearances in Disney works.
In The Little Mermaid television series, a Tyrannosaurus, accidentally released by Ariel, is among the dinosaurs causing havoc.
A T-Rex appeared in the television show Timon and Pumbaa.
A female Tyrannosaurus appeared as an antagonist in The Legend of Tarzan show.
A Tyrannosaurus is reincarnated by Experiment 210 in the episode "Retro" of Lilo and Stitch: The Series.
A Tyrannosaurus resembling the Fantasia one appeared in the episodes "Mom's Birthday", "Unfair Science Fair Redux (Another Story)", "Phineas and Ferb's Quantum Boogaloo", and "It's About Time!" of Phineas and Ferb; in the latter it was the main antagonist.
A Tyrannosaurus appears as one of many dinosaurs in Gravity Falls.
The Tyrannosaurus vs. the Stegosaurus
The Tyrannosaurus Rex and the Stegosaurus at Walt Disney World.