|Class Name :
Unknown, but probably prior to 2222 
|Length : 380 m 
Beam : 380 m
Height : 210 m
Decks : 60
6 x Heavy disruptor cannon , total output 180,000 TeraWatts
|Defence Systems :
|Standard  shield system, total capacity 486,000 TeraJoules
Standard Duranium / Tritanium Single hull.
(TNG scale) :
|Maximum speed unknown, but less than an Intrepid class starship 
|Strength Indices :
(Galaxy class = 1,000)
|Beam Firepower : 3,600
Torpedo Firepower : -
Weapon Range and Accuracy : 500
Shield Strength : 180
Hull Armour : 6.25
Speed : -
Combat Manoeuvrability : 250
|Overall Strength Index :
|Diplomatic Capability :
|Expected Hull Life :
Encountered by USS Voyager in the year 2372, 
this vessel was originally built by the Cravic. The Cravic were at war with the Pralor some time ago; both sides built large numbers of robots called Automated Units in order to do the fighting. When the two sides called a truce, they both decided to dismantle their robot armed forces. The Automated Units decided that their own builders had become a threat, and so turned on and destroyed them. The robots then continued the war between themselves according to their original programming.
The builders had anticipated the danger their creations posed, and as a result they designed each unit to be powered by an energy source which had a unique code built in. Since the robots were not able to do more than reproduce existing power sources, they were unable to replace themselves or expand their numbers. While this did not save the Pralor or Cravic, it did ensure that the robots would be unable to increase their strength significantly afterwards and pose a threat to other powers in the region.
When Voyager encountered a damaged Pralor Unit floating in space, they were able to repair and reactivate it. The unit subsequently abducted Voyagers chief engineer after a Pralor warship arrived, in an attempt to force her to create a general purpose power unit. Voyager was able to rescue Torres when a Cravic ship attacked the Pralor vessel. The Pralor and Cravic vessels appear largely identical in design.
Little is known about the capabilities of either the Pralor or Kravic vessels, and since Voyager is now far beyond their space it is unlikely that these ships will be encountered again. 
Seen in the second season Voyager episode "Prototype", little is known about the Cravic ship. Indeed, we don't even know for sure that the ship wasn't built by the robots themselves after the Cravic and Pralor were wiped out. Nor do we have more than a general indication of the size of the ship - I counted about 11 rows of windows on the bottom section of the almost identical Pralor ship, plus gaps for another four or so. Using this, I've come to a length of about 350 metres but this can only be regarded as a very general guess - the ship could easily be twice that size.
Sources for the few facts that we do know : that the Cravic ship mounts disruptors comes from a line by Paris; when Tuvok tells him that the Cravic attack has opened up a hole in the Pralor shields, Paris says "now all I have to do is dodge a few disruptor blasts". This differs from the Quantum resonance charges fired by the Pralor ship. It may be that both ships have both weapon systems and just chose a different approach to the battle for some reason, but that seems unlikely to me. Given the general closeness of the designs, I've assumed they are of equal size and basically even in other ways. The date of 2222 for the ship comes from PAU 3947, who states that he has been alive for 1,314,807 hours and 33 minutes - which works out to just about 150 years. That this applies to the Pralor and Cravic and that the ships predate this time are assumptions of my own.