Breen

Player Race: Heck no.
Relation to UFP: Non-agression treaty (signed at conclusion of Dominion-Federation war).

ACTDNoteworthy:
- Still considered enemies of the Federation.

Description
Humanoid civilization.  (Hero Worship -TNG).  Owing to the extremely cold climate of their homeworld, Breen do not have blood.  (In Purgatory's Shadow -DS9).  The Breen had outposts near the Black Cluster that were investigated by the Enterprise-D in 2368.  The Breen utilized cloaking technology and their ships were armed with disruptor-type weapons.  The Breen, politically nonaligned, were considered but dismissed as a possible explanation for the destruction of the S.S. Vico in the Black Cluster (Hero Worship -TNG).  In 2370, a Breen pilot participated in the palio on Deep Space 3 (Interface -TNG).  The Breen were not empathically detectable by Betazoids (The Loss -TNG).  The Breen were one of the civilizations who used type-3 disruptor weapons (Star Trek: Generations).  The Breen homeworld was a frozen wasteland.  (Crossfire -DS9). Among the Breen, pregnancy at a young age was a common occurence.  (Eloguim -VGR).  In 2366, two Breen warships attacked the Cardassian ship Ravinok.  The Breen ships chased the Ravinok to planet Dozaria and forced it to crash.  The Breen used the survivors from the Ravinok to mine dilithium on Dozaria.  To protect themselves from the heat of Dozaria, the Breen guards wore completely sealed, refrigerated suits (Indiscretion -DS9).  Breen privateers attacked the Bajoran colony of Free Haven in early 2372  (To the Death -DS9).  The Romulans have a saying:  "Never turn your back on a Breen."  (by Inferno's Light -DS9).
Star Trek: The Encyclopedia (1999 edition).

Civilization.  The Breen used spacecraft that employed biological technology (Scorpion, part 1 -VGR).  The Breen allied themselves with the Dominion during the Dominion war (Strange Bedfellows -DS9) and launched a devastating attack against the city of San Fransisco on Earth in late 2375 (The Changing Face of Evil -DS9).
Star Trek: The Encyclopedia (1999 edition) Supplemental