"Attack tower. Attacks nearby enemies inflicting massive damage within an effect area of 0.6 cells radius."
The Executor is one of the highest tier defensive turrets with long range, high damage, a fairly high rate of fire and a small area of effect. It can be researched in the Foundry for 3000 gold.
It can be built directly or upgraded from a Great Ballista.
Like units, Executors can be told to target either the nearest threats or the highest level ones. This can be useful in later stages of the game when the player has a significant number of troops capable of taking out tougher infected, as they have significant splash damage, though their high maintenance cost means they should be built somewhat sparingly.
Unlike Titans, Executors are not movable, which means they are useless and will be waste of gold and resources if built at wrong place. Be sure to build them where the final swarm comes.
Comparing to a Titan, an Executor has:
Unlike Great Ballista, Executor deals 100 damage to all targets hit per shot.