Cigarillo Lee is a small-time Brooklyn criminal, who tried to rob a liquor store but forgot his gun. After getting out of jail after failing his first-ever robbery, he joined up with Blackjack Bronson and the rest of the party to plan a bank heist.
He's young and relatively small. He has a "fresh and as-yet unbeaten face", which Zeke offers to correct.
He is naive and inexperienced, knowing very little about the criminal world. This is the second job he's ever been on, and waits for someone to order him around before taking initiative. He's terrified of Zeke, and listens to him without question.
He's a fair hand at shooting, and at listening to directions. He has a Sharps Big 50 rifle, the largest gun in the system, and a pistol. The rifle is too heavy and large for him to effectively use.
When fleeing from the hold-up on the bank, he rode his horse too hard and it perished.