The Lost Commanders

"The Lost Commanders" is the second season premiere episode of the animated television series Star Wars Rebels. After premiering at New York Comic Con on October 8, 2015, it aired on Disney XD on October 14, 2015. The episode features the return of the clone troopers CT-7567 ("Rex"), CC-3636 ("Wolffe"), and CC-5576-39 ("Gregor") from the Star Wars: The Clone Wars television series.

Official description
Ahsoka Tano sends the Ghost ''crew to Seelos in search of an old friend -- one whose leadership and strategy skills could help the fledgling rebellion. But will this legendary commander be willing to join the fight?''