Fish can be found in lakes, rivers, and the ocean. There are several different species of fish, all of which can be harvested with the fishing ability and move each time a creature moves.
Clown Koi
Clown Koi are a fairly large orange and black fish that resemble a clownfish mixed with a lion fish. They live in lakes and rivers. Catching them requires 2 fishing and they give 5 food when caught. Clown Koi also have a lifespan, and will die after a few days, at which point any creature that moves adjacent to them can pick them up.
Fish Swarms
Fish Swarms are schools of small grey minnow-like fish that live in freshwater and the ocean. Fish swarms will sometimes collect in seaweed and at the edges of rivers. Catching them requires 1 fishing and they give 1 food per fish. The higher fishing, the more food (ex. 2 fishing will catch 2 fish).
Razoranha
Razoranha are a predatory fish who will attack any creature who is bleeding in the water. This can make them VERY deadly due to the fact they act every time you make a move, meaning they can very quickly kill a creature if you don't notice them attacking. Catching them requires 4 fishing and they give 3 food when caught.