- Humans: In some stories, humans are portrayed as fearing or hunting mermaids, either for their perceived beauty or for their rumored magical powers.
- Sea monsters: Mermaids are sometimes depicted as being in conflict with sea monsters, such as krakens, sea dragons, or giant squids.
- Other mythical creatures: Mermaids may also be seen as rivals or enemies of other mythical sea creatures, such as sirens, selkies, or water nymphs.
These conflicts and rivalries are often used to create dramatic tension in stories and legends involving mermaids. However, it's important to remember that mermaids are fictional creatures, and any depiction of their enemies or conflicts should be taken with a grain of salt.