Corporal Tarr was a marine in Sergeant Strings' 4th Squad in the Bonehunters sent to conquer the Whirlwind. He was apparently nondescript, with pale, stolid features and had placid, pallid eyes.
He was known for his unyielding stance with a shield. It was said that once during training, Master Sergeant Braven Tooth had spent nearly two bells pounding on him with a mace but was unable to get past the shield.
Tarr thought that Corabb was trying to prove himself and outdo Tarr whereas in reality, Corabb stuck close to the corporal to protect the man's weak side even though it meant disobeying Fiddler's order of guarding Bottle.