Use a pteranodon to place it into a trap so it doesn’t move around. Then, kill fish and drag their bodies over to feed the otter. Remember: Do not harvest the fish’s dead bodies, drag it over once they are dead. The otter spawns in most rivers if there are otters on that map. These guys are furry, cuddly, and useful. They can store items for you with a 50% weight deduction on your shoulder and keeps you insulated in extreme temperatures.