Bio-cruiser are a cybernetic fusion of Terran aerospace technology and Zerg biological weaponry. During research on the new zerg known as the Corruptor, the Vaul became interested in the concept of infested warships. Being one of the most powerful units in the Koprulu Sector, the infestation of Battlecruisers was very influential in deciding what to adapt into the Vaul arsenal. While infested, these ships became airborne turrets that could attack both ground and air forces alike before eventually dying. Although this comes at a cost of mobility, the lost of such a powerful unit can be crippling to Terran forces. As such, the Vaul began to use advanced Xel'Naga cybernetics and evolutionary technology to improve the Zerg's infestation technique. What developed became the first generation bio