Overview: The schoolmaster is telling the class all about how to look after the school pet, a green crab. He then asks who would like to look after it. They all shout that they want to, with Pingu the loudest, and the schoolmaster chooses Pingu. Pingu goes up to have a close look, pats the crab’s claw, and the crab clamps him on the beak. He proudly takes the crab home and shows Mother and Pinga, putting the tank containing it on the table and taking off the lid. He pats the inside of the tank, and the crab clamps him on the beak again! While Mother is comforting Pingu, the crab escapes and is followed by Pinga. Mother and Pingu are then surprised to see Pinga and the crab together, with the crab colouring in Pinga’s drawing, and go to have a closer look. Mother goes off, and Pingu indicates that he wants the crab back in its tank. The crab bristles, clacks its claws at Pingu, and tries to bite him when he gets too close. Pingu momentarily turns away, and the crab scuttles off and hides. Pingu and Pinga look, but they can’t find it. Just then Father arrives home, picks up the paper and sits down in the armchair. He quickly gets up with a cry of pain, as the crab has been hiding under the seat of the armchair, has bitten him, and is now hanging onto his backside. Pingu is delighted that the crab has been found, but then Father pulls the crab off, carries it outside and puts it into the pool, ignoring the protestations from the rest of the family. Pingu is looking for the crab in and around the pool without any luck when Robby turns up. Pingu explains what has happened and Robby dives into the pool to look. After a while Robby comes up with a red crab, a yellow crab, a blue crab, a hermit crab and at last a green crab with brown claws. Pingu tells Robby to stop, Robby puts back the blue crab he’s just found, and both of them shoo all the other crabs except the brown-clawed, green one back into the pool. To Pingu’s surprise, the green, brown-clawed crab then offers to shake Pingu by the hand, and he gingerly accepts. The crab then jumps into Pingu’s arms to be carried. When Pingu goes back to school with the crab, he shows off a trick with the crab by balancing it on his head, the crab then jumping back into its tank. They all applaud. On the way home Pingu is very surprised to find Pinga being helped by a green crab to build a brick tower. The crab jumps into the pool and waves goodbye, they wave back, and the crab disappears underwater.