The Remora served as a transport for Echo while he was with the Clone Underground. This vessel, originally a mining ship, underwent modifications to enable stealth infiltration, rendering it suitable for covert entry and departure operations. This swift spacecraft also possessed a detachable leech vessel, named the Remora-one, for boarding actions.
During an attack near 18 BBY on an Imperial Advanced Science Division Gozanti-class cruiser, Echo piloted the ship with his team, which consisted of clone troopers Nemec, Fireball, and Gregor. The Remora obliterated the cruiser's engines and hyperdrive systems, in addition to providing support for the secondary craft until it successfully boarded the cruiser. Subsequently, Echo piloted the Remora to Pabu to meet up with his former unit, Clone Force 99. Following the rescue of Omega and Crosshair from Imperial captivity at Mount Tantiss, the team accompanied Echo on a mission to Barton IV to decode data from Nala Se's datapad that Omega had taken from the Tantiss Base.
Following their mission to Barton IV, Echo left the Bad Batch on Teth, where the base of operations for the Underground was situated, before piloting the Remora to a designated meeting place to collect Gregor. After retrieving Gregor, they made their way back to Teth, only to discover that Imperial forces had compromised their base. Echo piloted the Remora to an extraction point, where Rex, Howzer, and the Bad Batch boarded, enabling them to evade their pursuers.