Decided to have a crack at creating some drones and I thought I should start of with some nice and simple variants instead of a whole new enemy.
Bomb Drone:
The Bomb Drone is just like a normal tier 1 Drone except instead of a dense chest, it has a frame-like chest holding a large bomb in the center (an ever so slightly larger version of the bombs the Spider Drones launch). The bomb would have no timed explosion and will only set off if it gets hit by a weapon, this means players would have to be more careful about where they attempt to strike the Drone while engaged in melee combat, but could use it to their advantage with a bow if the Drone is close to other Drones.
Images can be found here: http://imgur.com/a/kHmqr
Defence Drone: (+ Bomb variant of the Defence Drone)
The Defence Drone is basically just a tier 1 drone with much better armour. The armour is made out of the same material as the sword so if an arrow or sword strikes it, they will be deflected. The armour would be slightly glowing just like the sword. Players would have to be precise with their attacks, landing them in the joints of the Drone to quickly defeat it. I also made a bomb variant of the Defence Drone because why not ¯\_(ツ)_/¯.
Images can be found here: http://imgur.com/a/NyGoX
Well, that's all from me today, hope you enjoyed :)