Leon Grimes
Grimes is a Sagittaron who survived the Fall of the Twelve Colonies. While it is not clear whether or not he was a prisoner aboard the Astral Queen, he vocalized his support for Tom Zarek, espousing that Zarek was a freedom fighter and hero. He was part of the Sagittaron delegation that boarded Cloud 9 with Valance, the believed-to-be assassin out for President Laura Roslin.
Grimes first gained the attention of Captain Lee Adama when Grimes tried to rough up a person who called Zarek a murderer and terrorist. Later on, Grimes attempted to assault the captain in a bar on Cloud 9, only to be subdued by Adama (with assistance from Kara Thrace).
During Adama and Thrace's interrogation of Valance, Adama claimed that Grimes gave him up; it remains unknown whether or not there is any truth to this, given their "good cop, bad cop" interrogation routine on Valance. What happened to Grimes after the altercation remains unknown as well (Colonial Day).