Build an adorable room decoration with 2 cute sea otters LEGO® Ideas Floating Sea Otters (21366) is a building set for adults that allows you to create a room decoration that is unbeatable in terms of cuteness. Create a magical model of LEGO bricks depicting an otter mummy with her son on her belly in the water. Place the young on the belly of the mother. Put the head, mouth, fins and claws of the mum in the right pose.