Blight Drone
Blight Drones are daemon engines of Chaos sworn to the service of Nurgle, the Chaos God of plagues. Seemingly a bizarre and unsettling cross between larva, flies, machines and daemons, these sentient weapons of war are attracted in swarms to battlefields heavy with the dead (just like flies). They are also known as Bilecysts which is just a few characters off from being mistakenly called a Bicyclist.
Overview
Armed with autocannons and maw-like openings called the mawcannon that spew acidic poisons capable of melting through flesh and metal, in their high numbers they can be overwhelming. The Mawcannon is a smaller version of the weapon found on the mighty Soul Grinder Daemon Engines, and acts as the Chem-Spewer to the Soul Grinder's preferred Warpfire (Basically, it is the Chaos Banewolf to the Chaos Hellhound...only that it could fly). They have been used in many recent chaotic actions and the Death Guard and the Purge seem to favor these machines, using them to confuse and cower the enemy.
Like most Nurglite engines, if a Blight Drone is destroyed in combat it invariably detonates in a shower of bile and pus, and is capable of causing extreme damage to everything caught within the blast.
The Blight Drone's brother is the Foetid Bloat-drone which has more tentacles to violate any enemy of the Plague Father.
They were in the Pauldrons: The Vidya as the main flying enemy in the Chaos forces. Most players quickly grow to hate the things, mainly because they take an enormous amount of hits to kill (as befits a Nurgle daemon engine), and because of that one time, where you are tasked to deal with two of the fuckers backed by a Chaos Psyker, while surfing the top of a Titan. Sounds cool? Well, it would be if it weren't because of those three enemies being infuriatingly hard to hit, tough to kill when you do, and the Titan lacking any kind of cover what so ever (use the port side tower above its shoulder as a wall). Oh, and the Titan moves all the fucking time, so say farewell to any kind of accuracy.
A interesting trivia to note. The size of the Blight Drone seems to vary depending on which media it is presented in. In the Space Marine video game, the daemon engine is roughly the size if not slightly larger than Captain Titus, however on tabletop, it is bigger in dimension to a Chaos Dreadnought.