Kanan Jarrus was a Jedi Padawan who managed to survive Order 66. He went underground for years and hid the truth about who he really was, carrying a blaster - an uncommon practice for a Jedi - in order to keep his past secret.
Despite that, he was every bit the Jedi and did what he could to help the Galaxy before becoming a full-blown Rebel alongside the rest of the Ghost's crew. Eventually taking on Ezra Bridger as his Padawan, Kanan battled the likes of Grand Admiral Thrawn and Maul before sacrificing himself to save his friends.
During Star Wars Rebels' final season, we learned that Hera Syndulla was pregnant with his child and Jacen made his live-action debut in Ahsoka last week.
When Hera and Jacen enter the Ghost's cockpit in this Tuesday's instalment, a photo can be seen of Kanan. His trademark ponytail and goatee are clearly visible, though it's unclear whether this is an actual shot of Freddie Prinze Jr. or a stand-in used because Lucasfilm knew we wouldn't be able to see more than a blurry outline!
Needless to say, speculation is now running rampant that we'll eventually see Prinze make a full-blown cameo appearance. However, that would contradict what he previously said about a possible return as Kanan in Ahsoka.
"I was asked to, yeah. I didn’t necessarily want to," he said of his recent voice cameos. "I feel like every time you hear Kanan’s voice since Rebels ended, it really kind of dilutes his impact. I didn’t want to do [The Rise of Skywalker] either. I was asked as a favor and I feel like all my - all their favors are used up now."
Asked directy whether he could show up in Ahsoka, the Rebels alum responded, "No Ahsoka, I’m done with Kanan. I’m too old for that stuff."
It's previously been reported that the show will feature Loth-wolves, with a stand-in putt reportedly named "Doom" on set. In Rebels, one of the creatures - an avatar of Kanan Jarrus' will in the Force - appeared before Ezra. Essentially a reincarnated version of the fallen Jedi - whose real name was Caleb Dume - this suggests the hero will have a presence in Ahsoka, even if Freddie Prinze Jr. doesn't make a physical appearance.
With the Multiverse about to come into play, that too could explain how the character makes a comeback...