Merfolk

A race of aquatic mammals that have evolved to charm wayward sailors.

Siren

Varies

Most colours

4-6' depending on species

100-200 lbs

Gills, retractable fins, some have fish-like lower bodies

a bit of variance

Mermaids typically steal the clothing of their prey to better conceal themselves within society.

Good sea legs, Echolocation

Obligate carnivores, Terrible at traversing on land

200 years

Many believe in Davy Jones and other old sailor's folktales

Independent; no rulers

Anything they can create from the sea around them

Many stow away as crewmembers on ships

No currency; all transactions are trading or bartering

Not all Merfolk are hostile towards humans.
There are saltwater, freshwater, and anadromous merfolk