A reptilian species bitterly opposed to their neighbours the Anticans, with both peoples seeking admission to the Federation.
The Selay are a reptilian humanoid people from the same star system as the Anticans. The two species have a long hatred for one another, and Anticans consider the Selay a source of food.
In the episode Lonely Among Us, the Enterprise-D carried delegations from both species to a conference that would consider their application to join the Federation. Keeping the two hostile delegations apart and from attacking each other proved a constant headache for the crew. At the same time, an energy being picked up from a cosmic cloud possessed several crew members and finally Captain Picard himself, adding to the chaos of the mission.