Mo the mermaid princess's friends have been captured by the evil pirate Vanilla Cringe. She plans to sell them to a collector and seeks Mo as her main prize. Just before capture, Mo makes a message in her magic moonstone and gives it to Errol. Can this seaweed pop guzzling monster to carry the message to his friends the Three Little Pirates and will they be able to save Mo and her friends from Vanilla Cringe before it is too late?