Ghost Droid

The Ghost Droid is a hostile droid first found at Mount Whirl.

Appearance
The Ghost Droid is green and slightly transparent, but the helmet is a solid green.

Its 2.0 and 3.0 counterparts appear similar to the original variant, but 2.0 is red while 3.0 is dark blue.

Behavior
When a player enters the Ghost Droid's aggro range or shoots it with a ranged projectile, it will turn invisible and begin chasing the player. It will only be revealed if it is damaged by a player.

If the Ghost Droid loses sight of the player while visible, it will turn invisible when it sees a player again.

If the Ghost Droid loses sight of the player while invisible, it will remain invisible.

While invisible, the Ghost Droid will periodically emit small ghostly icons at its location, helping you to track it.

Combat Tips
Ghost Droids have moderate health but can potentially deal a lot of damage. You should never let the Ghost Droid catch you off-guard.

If you can estimate the speed of the Ghost Droid well, it will allow you to attack it when it is close but not yet touching you.

If the Ghost Droid spawns along with other droids, you can use the other droids as a gauge to estimate where the Ghost Droid is.

Look out for the tiny icons that the Ghost Droid emits if you've lost track of it.

When it is chasing you, the Ghost Droid can be revealed early by hitting it with a projectile. Crossbows are better for this as they fire arrows in a straight line, while slingshots fire in a parabolic trajectory.

Trivia

 * For a brief moment after the Ghost Droid first spawns, if a player is in its aggro range the Ghost Droid will pursue the player without turning invisible.
 * If the Ghost Droid is hit with a ranged weapon while the player is on an elevated area, such as on top of a wall, the Ghost Droid will not react to being hit.