They do not use range attacks but they move around. Mario loses a life if he comes in contact. They can be found in the Bigmouth Galaxy and the Deep Dark Galaxy. The Jammyfish can be defeated by throwing three Green Shells or two Gold Shells at it. The Jammyfish leaves a Coin after its defeat.
In Super Mario Galaxy 2, it has the same role as in the first game appearing in the Cosmic Cove Galaxy however this time, it only takes two shell hits to kill it and it releases Star Bits instead of a Coin.