The Klingon Bird of Pray is a staple of its fighting force. It is small (~110 meters in length) highly maneuverable and carries powerful pulse disruptor cannons (2) as well as photon torpedo launchers (fore and aft).
The ship has a maximum speed of Warp 9.8 and is equipped with a cloaking device. The only weakness of the ship is that it cannot fire while cloaked and some older models (in the 24th century) have a vulnerability in their primary plasma coil as part of the cloaking system that has the potential to be triggered under the right circumstances.
Any single ship of this type is a dangerous foe, when combining forces they can quickly become an overwhelming force with few numbers.
There are many different classes of this ship in use by the Klingon empire and some discontinued classes have ended up in shipyards in Federation space for sale.