Class D-12 Bird-of-Prey
The D-12 was built in the 2350s and was eventually retired due to defective plasma coils in their cloaking devices.
In 2372, Klingon sisters Lursa and B'etor used this type of vessel when they assisted Soran with his plans regarding the Nexus energy ribbon. The Duras sisters later attacked the Enterprise-D, after acquiring the frequency of the ship's shield harmonics. Ironically, the D-12's design flaw was what allowed Enterprise to destroy the ship.