Dee'Ahn's species was a humanoid species which had traveled as far as Risa and Pernaia Prime in the mid-22nd century. They were characterized by vaguely bat-like features, with large pointed ears and wrinkly, pink skin. They had the ability to shapeshift to appear as humanoids of other species and other genders.
In 2152, Commander Charles Tucker III and Lieutenant Malcolm Reed made an unfortunate encounter with two members of the species, calling themselves Dee'Ahn and Latia, in a nightclub on Risa. They had taken the shapes of two beautiful women, in order to lure unsuspecting victims into remote areas of the pleasure planet, then change into their natural appearance and rob them. (ENT: "Two Days and Two Nights")
One member of the species was a guest in a bar on a moon of Pernaia Prime in the same year, when Captain Archer, Sub-Commander T'Pol, and Ensign Travis Mayweather searched for Menos. (ENT: "The Seventh") Another member of the species was a prisoner on an Enolian transport on its way to Canamar, the following year. (ENT: "Canamar")