The crabs are pair of crustaceans. They live on the beach and like to make music to rhythm of the rain.
When Steve noticed a rain cloud pouring rain near the distant island, the crabs scuttled onto the shore from the right, the 1st crab calling to him twice. When he noticed them, the first crab told him that they made up a dance to the sound of rain. After Steve stated that the rain dance was cool, the 2nd crab asked him which of them was dancing to the rhythm of the rain. As he did, both crabs danced differently: the 1st crab slowly snapped his claws 3 times to the right, then slowly tilting to the left and snapping its claws once before repeating the process, all while its eyes were closed; while the 2nd crab quickly snaps its claws.
Both crabs have red bodies, claws, and eyelids with dark red arms, legs, and eyestalks. Each has yellow eyes with black pupils on stalks.
The crabs have only appeared in "Blue Wants to Play a Song Game".