Starfish are failed murder weapons and characters who only appeared in Kung Fruit. They are parodies of ninja stars (Hira Shuriken) and were used by Coconut for the same reason. They are the first sea animals and echinoderms in the series.
They were used by Coconut in order for him to take power of the kitchen. One of them got stuck in Midget Apple's head, while another one got stuck in Marshmallow's. The others thrown at them missed. Marshmallow's starfish talked and appeared to be a very kind creature, telling the Marshmallow he loved him. The one stuck to Midget Apple does not have any speaking lines and was removed when Midget Apple was caged. It is implied that Marshmallow's starfish and his friends were thrown against their wills as he was also excited when Coconut was defeated, implying he didn't like Coconut either, or just wanted to cheer along with Marshmallow and the gang.