Paxan

The Paxans are an alien race native to the Alpha Quadrant.

Physiology
Nothing for sure is known about them save that they might possibly be an energy-based species.

Culture
Highly xenophobic of other races, they standard that they placed their entire planet in their home system with a field that generates the effects of a wormhole but actually stuns the crew so that the Paxans can erase their memories of the encounter.

Source

 * Star Trek Next Generation: "Clues"