Scooby-Doo! Legend of the Phantosaur

Plot

Shaggy Rogers learns he has a disorder causing irrational overreaction to frightening stimuli and fears he can no longer be part of Mystery Inc. His friends take him to a spa in La Serena to calm down. There they meet spa owner and hypnotherapist Mr. Hubley, paleontologist Professor Svankmajer, and her assistant Windsor, who oversee a dig. When a large ghost dinosaur attacks, Shaggy is paralyzed with fear, but Scooby-Doo rescues him before Fred uses the Mystery Machine to knock the dinosaur off a cliff.

Hubley explains the ghost dinosaur is the Phantosaur, a legend of a dinosaur summoned by Native Americans to reclaim land from colonists. He hypnotizes Shaggy to switch between his regular personality and a fearless persona upon hearing a keyword, but nobody remembers it. Fred, Daphne, and Velma investigate the dig site for dinosaur tracks and snake-like trails. Shaggy fights a biker gang at a buffet and is invited to a motorcycle race after hearing the keyword 'bad'.

Daphne and Fred see mining company members retrieving a dinosaur tooth. Daphne teaches Shaggy to ride a motorcycle, and after hearing the keyword again, he races and rescues biker leader Tex from a cliff. The Phantosaur and Velociraptors interrupt the race. The gang and bikers flood a mining company van, revealing the Phantosaur was an animatronic operated by someone wanting to scare off Svankmajer's team to access a silver mine.

Hubley arrives saying his hypnotherapy equipment was stolen. Mystery Inc. encounters another Phantosaur before it disappears.

Ultra Instinct Shaggy meme

On October 12, 2017, YouTube user Midya uploaded a video titled 'Ultra Instinct Shaggy' featuring an edited scene of Shaggy fighting Tex's biker gang. The title references the Dragon Ball Super form Ultra Instinct, and the video uses the track 'Kyūkyoku no Battle' with slowed footage to make Shaggy appear to have gained the power. The video went viral and became part of a wave of memes depicting Shaggy with superhuman abilities, often requiring only a small percentage of his power to defeat opponents.

Variations use frames from a behind-the-scenes featurette of the 2002 film Scooby-Doo with fake subtitles. The meme's popularity coincided with Mortal Kombat 11 development, leading to a Change.org petition to include Shaggy as DLC. The petition gained thousands of signatures and attention from Mortal Kombat co-creator Ed Boon and Shaggy's voice actor Matthew Lillard. Lillard tweeted support, and Boon jokingly petitioned to include Scooby-Doo in Injustice 2.

Shaggy was later confirmed not to appear in any Mortal Kombat games. The meme was referenced in the animated film Mortal Kombat Legends: Battle of the Realms, where Shaggy appears from the Warner Bros. Animation logo with a glowing aura and green eyes, grabbing Scorpion. It was also referenced in the video game MultiVersus, where Shaggy is a playable character who gains superpowers after eating rock candy, and some of his lines quote the film verbatim.