Stardew aquatic animal is a valuable catch in the Harvest Moon game. This heart eel can be found in the river during rainy weather and at night. If you manage to catch a Cosmic heart fish, you can sell it for a decent sum of money. In addition to its worth, it is also in demand by fishing enthusiasts for its ornate beauty. So, grab your tackle box and head to the riverbank to try your luck at catching this Cosmic heart fish. Happy fishing!