Defense Drone

The Defense Drone is a robot that is located on SkyTown, Elysia and is the second boss fought there, after the Steamlord. Samus is ambushed by this mechanoid when she tries to aquire the Boost Ball. This trap was likely set up by the Elysians (to test those who wish to have the Boost Ball) or Ghor.

Description
The Elysians designed the Defense Drone to guard key areas in SkyTown, however only one is ever encountered. The Defense Drone's appearance is a bronze, two-legged, dome-topped tank. Armor covers the entire outside of the unit, protecting it from harm. A feature at the "tail" of the mechanoid looks similar to a rib cage. A large cannon protrudes from the base of the unit and is used for multiple attacks. A single yellow eye is the unit's main optical device. Three antennas are located above the robot's head, which can be damaged by Beams fire. After all three antennas are brought offline, the mechanoid will be stunned for a period. This allows the robot's optical device to be damaged by the Grapple Lasso, which causes an eratic spinning motion of the eye revealing the unit's control mechanism. The dome splits into two parts, and the control device is vulnerable to weapons fire. After the Defense Drone becomes critically damaged, the unit emits a deep fog that covers the area and impairs Samus' view.

After the Defense Drone is defeated, it short circuits and collapses, then blows up. The locking device that held the Boost Ball upgrade in place deactivates and the upgrade appears.

Logbook entry
Metroid Prime 3: Corruption: "The Defense Drone is used to secure key areas within SkyTown. The externally mounted antennas are tied into the unit's optic array. By destroying all of the antennas, the optic array will overload and be vulnerable for a short period. The machine's Control Unit is also vulnerable, but must be exposed to be targeted. Its armor is immune to small-arms fire."

Attacks
Offensively, the Defense Drone is very well equipped. The main cannon features a homing plasma Bomb launcher, and lock-on missles. Both these attacks need to be charged for a brief period. The Plasma Bomb can be destroyed with an Ice Missile. Fewer missiles can be fired without charge. The feet are equiped with a booster for propelling the unit far for jumping, and also to slow the speed when falling. They also can create large, expanding electric shockwaves after landing. When the control unit is revealed, the Defense Drone will jump to high ledges around the room. It will then fire homing mine balls, which explode and splatter on impact. These can be destroyed with several shots, and are made as a distraction from damaging the Defense Drone's control mechanism.

Trivia

 * The Defense Drone's broken parts also appear in a Diorama in the game's Extras menu (shown right).
 * The Defense Drone resembles the ED-209, a large two-legged mechanoid from the first Robocop film.
 * The Metal Gears from the games of the same name also look similar to the Defense Drone. Both the ED-209 and Metal Gears were developed as Bipedal tanks. They share this with the Defense Drone.