Joopa Base was a modified AT-AT repurposed by the clones Gregor and Wolffe to serve as their mobile headquarters. The AT-AT originally served under the command of Agent Kallus, sent to destroy Rex and the Ghost Crew when they were reported by Wolffe. Though the clones' AT-TE was destroyed, the rebels commandeered this walker and destroyed the other Imperial walkers. After the battle, Rex went on to join the Rebellion while Wolffe and Gregor remained on Seelos using this walker as their new home, naming it "Joopa Base." Over time they repurposed parts of their former AT-TE in order to modify their new home to include a landing pad.