Scooby-Doo on Zombie Island

After years of solving monsters that turn out to be costumes, Mystery, Inc. grows bored with the gig. Daphne and Fred launch a real-ghost-hunting TV series and savor the possibility of authentic scares. Fred reaches out to Velma, Shaggy, and Scooby to reunite for Daphne's upcoming birthday adventure.

Fred reaches out to Velma, Shaggy, and Scooby, proposing a reunion for Daphne's birthday. The plan doubles as a chance to scout real hauntings for Daphne's show. The idea tugs at the team's old camaraderie and curiosity.

The group hits the road, traveling across the U.S. in search of credible hauntings for Daphne's program. They encounter more fake monsters, testing their skepticism and old teamwork. The trip becomes less about scares and more about reconnecting as a team.

They arrive in New Orleans and hear rumors about Moonscar Island's haunting. Lena Dupree invites them to visit her workplace and explore the island, sensing valuable material for Daphne's show. The invitation promises mystery, though the gang remains skeptical.

They accept Lena's invitation and head to Moonscar Island, curious about its pirate legend and voodoo rumors. They meet the ferryman Jacques, Lena's employer Simone Lenoir, and Simone's gardener Beau at the island's edge. The group continues toward the mansion, unsure what they will find.

Shaggy and Scooby first encounter Moonscar's ghost, who briefly becomes a zombie near the island grounds. The rest of the group observes more eerie phenomena and begins to suspect something more dangerous than a simple illusion. They push forward despite the ominous signs.

That night, a horde of zombies chases the group through the grounds and mansion corridors. Fred and Daphne manage to capture one zombie, and Fred mechanically pulls its head off, revealing it to be a human in disguise. The discovery shakes their assumptions about the haunt.

During the escape, Daphne accidentally causes Fred to drop his video camera into quicksand, losing crucial film evidence for the show. The loss complicates their ability to prove or disprove the supernatural claims on camera. The team regroups and continues to search for answers.

In a cave, Shaggy and Scooby stumble upon wax voodoo dolls that eerily resemble Fred, Velma, and Daphne. They unknowingly activate the dolls by playing with them, briefly influencing their friends. A nest of bats adds to the chaos before the pair can warn the others.

The rest of the gang and Beau discover a hidden passage within the mansion that leads to a secret chamber for voodoo rituals. Velma confronts Lena about her lies, having deduced real footprints instead of drag marks. Simone and Lena reveal themselves, along with Jacques, as werecats preparing their immortality scheme.

Simone explains the island's forgotten history: settlers worshiped a cat god, Moonscar's crew attacked, and the survivors were cursed with immortality. The werecats drain victims to preserve their lives, and Jacques joined them to gain his own immortality. The zombies and ghosts on the island are said to be past victims awoken on harvest moons.

Shaggy and Scooby disrupt the draining ceremony, giving the others a chance to break free. The werecats close in on the group but realize too late that the harvest moon has passed, causing them to disintegrate into dust. The zombies' souls are freed and the lingering danger eases.

Beau reveals himself as an undercover police officer investigating disappearances on the island and helps resolve the case. He ends up sharing his stake in the investigation and offers to help with Daphne's show as a guest star. The team acknowledges his role as an ally and the tension on the island resolves.

With the danger gone, the group prepares to leave Moonscar Island at dawn. Daphne asks Beau to guest star on her show, signaling a new partnership and a future for their adventures. The group departs, already talking about the next mystery to chase.