Abaddon's species were a humanoid race native to the Delta Quadrant.
They were encountered by the Federation starship USS Voyager in 2376 in the form of Abaddon, the owner of Abaddon's Repository of Lost Treasures. The program of a shuttle that would be known as Alice manifested itself to Abaddon in the form of this species. (VOY: "Alice")
At least one female member of this species had been assimilated by the Borg and was a member of Unimatrix Zero. (VOY: "Unimatrix Zero")