The alv in the mythos world (novels & stories by Nathan Squiers & Megan J. Parker) are an inhuman creature that were referred in the literary couple's notes as "if sharks were made man". The alv, who have a tendency to wear heavy leathers & motorcycle gear, have pitch-black eyes and multiple rows of teeth like that of sharks'.
Under the water the world was so much different. There was no up or down, no left or right. There was only the pull of the currents that guided you, the steady tug of a flowing stream. All you had to decide was whether or not you would follow.