Anonymous says:
On Volcano Island, a couple of crabs, led by the Wise Crab, are enacting a ritual to send 9 heroes there to save their island. But the Mawgu, an evil being, brings the ritual to a halt, scattering the heroes. Danny Phantom and SpongeBob SquarePants fall from the sky and end up with the Wise Old Crab, and he explains why they were dropped here: The Mawgu was an ancient enemy who escaped his prison, and seeks vengeance, using a toxic ooze which corrupts everything it touches, but the prophecies say that "The Chosen Ones" will save them. The Crab trains them and tells the heroes to follow him so that he can direct them to camp. The heroes stop various enemies, and then find Patrick. They then go Shipwreck Cliff and rescue Tucker from repeatedly regurgitating giant seagulls. They then find camp, and are given the mission to find the "Night Girl (Sam Manson)" and the "Whiny Cephalopod (Squidward Tentacles)", and they are found.
Timmy Turner is then found at Fort Crabclaw with a Jimmy Neutron communicator which fell from the sky. However, the machine has no batteries. The heroes are then sent to destroy The Great Carapace, a giant sand monster with a wooden shell. They destroy the shell and push the monster into a waterfall by using catapults and coconuts. They are then rewarded with a jewel, which is the battery for the communicator. They talk to Jimmy using the communicator, and Jimmy explains that Mawgu is using a Rip in Time and Space to steal energy from all the worlds and keep it all for himself, and if he succeeds their worlds will be destroyed. Then Jimmy sends Tucker plans for the Neutronic Rip- Zipper, a device that recovers all the energy Mawgu stole and closes the Rip. The parts they need for the device are scattered across the Island. Then the wise old crab says that he knows where the last hero is, the deep sea squirrel (Sandy Cheeks) after they climb a pyramid, they find Sandy fighting Monsters. After the heroes help her they find the first part for the rip-zipper behind a crystal wall. After the Nicktoons gain all three Rip-Zipper items, they go in the Volcano, and find The Mawgu, whom transports them between Time and Space. The Nicktoons then succeed in defeating Mawgu, imprisoning him within the Rip, and closing it.
The heroes are praised for the save of the island and Jimmy is able to activate a portal to send them home. It shows at the end, that the heroes heads' are carved on the side of a mountain.