A hermit crab who has outgrown his old shell moves into a new one, which he decorates and enhances with the various sea creatures he meets in his travels.

"Hermit Crab has outgrown his shell; it's time for an upgrade. The beach is strewn with options, but none are quite right. A rock is too heavy; a tin can is too noisy; a fishing net too many holes. When a giant wave sends Hermit Crab careening toward a hungry porcupine fish, there can be no more dillydallying. He needs a new home to hide in -- and fast!"--

Ten little hermit crabs who go to the beach disappear one by one.

Platypus thinks he has found the perfect curly shell for his collection, but it keeps disappearing.

A seagull is enjoying a perfect day until a disagreeable crab comes along, but by sunset, they have discovered what really makes a day perfect.

Edgar the shark is getting the house ready for a visit from Santa Shark, and although he is skeptical, his friend Lotta the crab pitches in to help--but Edgar is worried about the lack of snow under the sea.

Scales and Sebastian decide that the other's life is much easier, so they switch.

Crabby is a very grumpy crab, so Plankton tries to find a game that will cheer Crabby up, but Crabby does not want to play Simon says or hide-and-seek---will a game of tag be more to Crabby's taste?

Six stories about the activities and experiences of a first grade class.