The Sentry Drone is a flying robotic suicide bomber. When you hear its antigrav engines revving up, you know you're in for a world of hurt.
It is a highly intelligent machine, capable of evading incoming fire to ensure that it reaches its target to deliver its payload. Other than its explosive payload, it has no weaponry, and makes up for this with a tough armored shell. It is fast-moving, and designed to deliver pain where it's not welcome. It appears to be a human invention like the turret, but reprogrammed by the aliens to see humans as enemies.
The Sentry Drone is a bulbous yet sleek metal sled. It has a grey and green camouflage paint job. It has two red LEDs and some sort of grill on its front, which look like a sinister face (particularly as nearly all other enemies have red eyes). It sports a pair of small fins on its dorsal section.
The Sentry Drone's only form of attack is by exploding at point-blank range. To support this design concept, it has no other weaponry, tough armor that protects it from being destroyed before it reaches its target, and is very agile.
It is so agile, in fact, that it can evade any projectile weapons. Being mechanical in nature, it is also immune to the Shrink Ray.
When it flinches from incoming fire, it will shudder from side to side, perhaps for a similar reason to the Turret . While it does this, it cannot move closer to the player, meaning it is an effective way to stall the Sentry Drone from reaching the player. However, this requires sustained fire, as it will recover almost immediately when it is no longer being hit and will continue back towards the player. This makes the Sentry Drone much more dangerous in situations where there is something else to distract the player (particularly if that "something else" is another Sentry Drone or two).
The Sentry Drone is able to open doors to chase a fleeing target, but it will not recognize whether there are any obstacles between it and its target. It is therefore possible to make it self-destruct when there is an obstacle between it and the player that would mean the player takes no damage from the explosion. This is because the trigger that causes the Sentry Drone to self-destruct is proximity to its target, not a clear line of sight between it and itself.
The best weapon to use against the Sentry Drone is the Chaingun Cannon, as it provides a high rate of continuous fire that keeps the Sentry Drone flinching (and thus keeps it away from the player). However, since the Chaingun Cannon loses accuracy at a distance, the Sentry Drone needs to be at least close to the player in the first place for this weapon to work effectively. The Shotgun works in a similar way.
The worst weapon, aside from the Shrink Ray, is the Laser Tripbomb. There is simply no way to deploy them for use against the Sentry Drone.
The Sentry Drone in other games
- The Sentry Drone cannot be shrunk by the Shrink Ray.
- The Sentry Drone is only ever encountered above water, and cannot submerge itself.
- The Sentry Drone was initially planned to be an armed "Snake Head", as the sound files for the Sentry Drone are mostly affiliated with the name "Snak" (a slightly shortened "Snake").
- In the LameDuke art files, there are sprites of two different armed flying machines, although it is unknown if they are related to the "Snake Head"/Sentry Drone. The green (bigger) variant is seen launching a rocket in the title screen of the game.
- There is some unused code in a CON file that would allow the Sentry Drone to be shrunk by the Shrink Ray. The code makes the actor stay shrunk until it ceases to exist, and it cannot be stomped on while shrunk.
- The Sentry Drone is almost non existent in The Birth episode. They made two brief appearances in It's Impossible and XXX Stacy.
- In Duke Nukem: Total Meltdown, there is a new enemy that is related to the Sentry Drone. Its appearance is quite different to the Sentry Drone, but it has the same abilities. It is an underwater version of the Sentry Drone, and is only ever encountered underwater.
- In the Sega Genesis port the Sentry Drone only needs one shot from any weapon including the Mighty Foot to destroy.
- One of the Sentry Drone sound effects is the same of one used by the imps of Doom.