Dee'Ahn's species was a humanoid species who 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.
Commander Charles Tucker III and Lieutenant Malcolm Reed made the unfortunate encounter with two members of the species, Dee'Ahn and Latia who had taken the shapes of two beautiful women on Risa in 2152, in order to lure unsuspecting victims into remote areas of the pleasure planet to change into their natural appearance and rob them. (ENT: "Two Days and Two Nights")
One member of the species was a guests in the bar on Pernaia Prime's moon in the same year, when Captain Archer, T'Pol, and Travis Mayweather searched for Menos. (ENT: "The Seventh") Another member of the species was one of the prisoners on an Enolian transport on its way to Canamar the following year. (ENT: "Canamar")