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A Heavy Raider is a Cylon dual purpose attack and transport spacecraft, analogous to the Colonial's Raptor vehicle. It is nicknamed a "turkey" by the surviving Colonial Fleet's military units (TRS: "Maelstrom").
The Heavy Raider shares many design similarities with the rest of the Cylon Fleet, featuring an autonomous bio-mechanical design. However, this craft is also easily piloted by Centurions or Humanoid Cylons if needed. The Heavy Raider has no windows, and any Cylon piloting the craft must rely on telemetry delivered to a Datastream inside the craft for operation (TRS: "The Farm", "Deadlock").
The Heavy Raider typically carries two tri-barreled automatic cannons capable of high rates of fire. These are further augmented with ship to ship missiles, which can be easily disassembled with the Raider's DRADIS dish into anti-aircraft batteries for use on a planet's surface (TRS: "Fragged").
The Heavy Raider was developed sometime during the forty year Cylon exile from Colonial contact. It took the Colonials by surprised when they were utilized to attack the Colonies at the onslaught of the Fall. Helpless people were left to watch as Centurions marched out as the ground invasion began ("The Plan").
Since the Fall, the Cylons have utilized the vehicle in their fleet, by deploying them alongside the autonomous Raider as a means of defense, deploying one for every ten or so Raiders (TRS: "Resurrection Ship, Part I", "Flight of the Phoenix").