The players controls torrasques in the Ultralisk evolution mission and can choose to permanently upgrade their ultralisks to torrasques after completing the mission. They are a counterpart to the noxious strain. Torrasques are also available in the mission "Amon's Fall."
Upon death the torrasque ultralisk will enter a cocoon and rapidly regenerate, restoring the torrasque to full health. Reincarnate has a 60-second cooldown; if the ultralisk is killed while in the cocoon or while reincarnate is on cooldown, it will die.
Thanks to the reincarnation effect, the torrasque strain has far more staying power than the noxious strain, effectively forcing enemies to kill it twice, in addition to tanking damage in its cocoon form which will be healed once it hatches. It also has innately higher armor and HP. Combined with the Tissue Assimilation upgrade to afford it healing, the torrasque becomes very hard to kill. As a trade-off, the noxious deals far more damage to enemies than the torrasque.
When using the torrasque strain, players should take time to pause between engagements, to allow their reincarnation cooldown to wear off. Being too hasty in the attack will result in wasted torrasques.
Near the start of development for StarCraft II: Heart of the Swarm the art team requested a concept of the original torrasque, the concept would be partially completed as a model during development but not make it into the final product.