Term used for both mermaid and mermen, but also any other mer-being. A mermaid is a legendary aquatic creature traditionally seen with the upper body of a human (human_torso) and a fish_tail (mermaid_tail) for a lower body. On e621, these should be tagged as humanoid_merfolk (but not humanoid).

On e6AI, this term is also used to describe several creatures beyond that initial definition, including:

• Beings with an anthro's torso and a fish's tail
• Beings with other forms of aquatic life as their lower half (for example, octopus, jellyfish)
• Fish anthros, where the upper half is humanoid and the lower half is fishlike. (A fish naga, if you will)

Generally speaking, a fishy lower half is a requirement.

There are many takes on merfolk out there. However, just because something says it is a merfolk doesn't mean that it is. Magic: The Gathering has a species of aquatic humanoids that used to have fish tails, but have shifted to be bipedal in recent years.

See also

• undine
• siren
• split_form