The Zerg had eventually gone very advanced on the infestation on the Terrans, and now it had reached one of the most dangerous arsenal of the humans, the targeting nuke, by infesting their Ghost Academies, where the warheads are produced. The infested Ghost Academies don't create warheads like ordinary ones, but keeping the radioactive materials inside them in sacs similar to Zerg cocoons by using its extra organs from the infestation called "Wrapping Tumors". Wrapping Tumors can create one sac at a time just like normal Ghost academies. the Zerg nuclear warheads are called Meteor Cocoons.
Similar to the advanced Nydus Network, Meteor cocoons can be launched in any target area that the fog of war has gone. It can launch its radioactive arsenals by themselves withoout any requirements of targeting units like the Terran Ghost. The Meteor cocoons seems to deal less damage than Terran Nuclear missiles when explode in action, but when a Meteor Cocoon hits the target area, it also leaves some radioactive waves around the area it explodes, causing critical damages to everything the radiation can reach. The radiation lasts quite a while.