Lassa Rhayme was a Pantorian pirate introduced in the Dark Disciple prequel short story “Kindred Spirits” by Christie Golden. Rhayme was the leader of the Blood Bone Order pirate gang and captained the starship Opportunity.
In “Kindred Spirits” (which like Dark Disciple took place during the Clone Wars) Rhayme crossed paths with Asajj Ventress. If you’re interested in reading “Kindred Spirits” you can find it in Star Wars Insider 159 and in the paperback edition of Dark Disciple.
Rhayme was only mentioned in Dark Disciple, but she re-appeared in Golden’s novel Battlefront II: Inferno Squad, which takes place after the destruction of the first Death Star. So she’s clearly good at being the leader of a pirate gang.
Lassa Rhayme could very well pop up in future Star Wars books or comics written by Golden or other Star Wars authors.