Background information Edit
Dopterian's were only identified by name in dialog in the episode "The Forsaken". According to the stage directions in the script for that episode, the Dopterian who robs Lwaxana Troi was described as a "small, weasely [sic] looking Dopterian who looks like a distant cousin to a Ferengi". (Star Trek: Deep Space Nine Companion - A Series Guide and Script Library)
Dopterians also shared an unusual resemblance to the Kobheerian species; their appearance was almost identical, but Dopterians had Ferengi-like noses, whereas Kobheerians had two large, elongated flat nostrils in the place of a nose.