Cosmic fish is a valuable catch in the Harvest Moon game. This fish can be found in the river during wet days and at night. If you manage to reel in a Stardew eel, you can sell it for a good price. In addition to its price, it is also coveted by anglers for its exquisite appearance. So, grab your tackle box and head to the creek side to try your luck at capturing this Galactic love creature. Happy fishing!