Selkies are elusive creatures, even in my attempts to find and define them. However, after some research some facts can be collected, though some contratict others.
Selkies as a mythological creature appear to live in water, and seem to have some similarities to Sirens. Some pages mention that they have an alluring song.
In the Final Fantasy Crystal Chronicles video game series, Selkies are human-like agile creatures with odd hair colors, including baby blue, pink, and green. They are the only race capable of double-jumping.
In some games they use bows, while in others they use what appears to be tennis rackets.
The king in Final Fantasy Crystal Chronicles Rings of Fate is a Selkie, and his daughter is a Selkie-Clavat mix.