The following section contains information from a previous version of StarCraft II which is no longer valid.
In the first phases of development the Corruptor were ground units.
Corruptors used to convert enemy air units into turrets. The attack was technically a debuff, which lasted for about two seconds. If that unit was destroyed during this time, it became corrupted, regardless of which unit landed the final blow. A corrupted unit became a stationary turret on the side of the zerg player.
The attacked unit
Corrupted units could attack ground and air units as well as structures. The player can control them, forcing them to attack certain targets.
Corrupted units had a limited life span and would eventually die on their own. A ground unit affected by Anti-Gravity will return to the ground.
When corruptors attacked an enemy force, the opposing player must decide whether to destroy any corrupted units, whether to try to kill the corruptors, or whether to retreat.