A rat is wandering the sewers of New York, when he stumbles upon four baby turtles, rolling in green ooze. He gathers them up and gets the ooze on himself. The next day, he notices he and the turtles have changed in size and decides to raise them.
A rat is shown scouring the streets for food and heads into the sewers. Meanwhile, A young boy walks out of a pet store, with four baby turtles. A blind man walks out into the street, with a truck heading his way. Someone notices and heads to help the old man. He manages to save the old man, but bumped into the boy, making him drop the turtles. The truck dodges the man, but a canister of green ooze falls out. The boy tries to get his four turtles, but is not fast enough Along with the ooze, the turtles wash into the sewers, where the canister cracks and the ooze spreads over them. Suddenly, the rat finds them and gathers them in a soup can. The rat creates a burrow and sleeps. The next morning, he wakes up and sees the turtles have grown. He too, has grown into a humanoid rat. He then leaves to gather food and sees the turtles are following him everywhere. He finds a pizza box and takes it back to the burrow. He takes a piece and the four turtles rapidly chew it up. The rat builds them beds and lays down in his burrow. They go to sleep and wake up to more pizza, the next morning. Before that, the smallest turtle crawls in his burrow. The turtles again follow the rat, who is searching for bed stuff, food, and drinks. The turtles find a box of pizza and hints at the rat to take it, so he does. The rat then finds a dirty messed up robe and puts it on. In the end, the rat decides to raise the turtles, since they seem to follow him everywhere, so he tries to think of names for them. He then finds a renaissance book, and thinks about the names he should give them.