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Scar is the nickname for a particularly vicious and cunning Cylon Raider, feared and revered by Galactica's pilots. The nickname is derived from battle damage and grime on the Raider's forward cowling that resembles a scar.
Scar is responsible for many ruthless, successful attacks against mining vessels deployed from the Fleet into a treacherous asteroid field. It is known for its taste for nuggets and favors separating them from their wingmates for an easy kill. The need to eliminate Scar's threat increases a pilot rivalry between Captain Kara "Starbuck" Thrace and Lieutenant Louanne "Kat" Katraine.
On the 29th day of mining operations, Starbuck engages Scar but breaks off a suicidal run against it in favor of luring it into the sights of her wingmate, Kat, who scores a crippling blow on Scar. Scar is sent careening into an asteroid, and is destroyed in an explosion of shrapnel and gore.