Text (TS): 2/4, Flying. ; Whenever ~this~ blocks or becomes blocked by a non-Wall creature, destroy that creature at end of combat.
Protection from Green does not prevent the Cockatrice's power because the ability is not a targeted effect. [WotC Rules Team 1994/02/07]
The ability destroys the creature at the end of the combat, which is after all first strike and normal damage dealing is done. This means that a creature may have to regenerate twice to survive the combat, once from damage and once again at end of combat. [D'Angelo 1996/12/09]
