The first episode of The Book of Boba Fett took time to explain what happened to Boba Fett after he fell into the sarlacc pit at the Great Pit of Carkoon in Return of the Jedi, right before Jabba the Hutt was killed by Leia Organa and Jabba’s Sail Barge was destroyed by Luke Skywalker.
We knew that he survived, given the events of The Mandalorian, but this series filled in some of the details about how it happened. But it also revealed that another fan favorite survived as well. Already we knew that Boba Fett survived the sarlacc pit and that Bib Fortuna survived the explosion of the sail barge, both of which were confirmed in The Mandalorian season two. But the first episode of The Book of Boba Fett confirmed that Max Rebo did as well!
Max Rebo was a well-known performer who specialized in playing Jill music as he led the Max Rebo Band, and he did so by playing the organ with his feet. By the time of Return of the Jedi, set around five years prior to the timeline of The Mandalorian and The Book of Boba Fett, he was playing at Jabba’s Palace as entertainment, and he and his band later traveled aboard Jabba’s Sail Barge to witness the executions at the Great Pit of Carkoon. Things didn’t go as planned for Jabba there, however, and he was killed and his barge destroyed. The debris rained down over the desert sea, but Rebo survived.
He would go on to play at Garsa Fwip’s cantina in Mos Espa by the time of The Book of Boba Fett, as he was seen playing there for entertainment as the others in the cantina partied and gambled.
Rebo’s cameo in the episode really had no significance to the plot, but plenty of significance to Star Wars fans who took a liking to him. He was a unique-looking alien who played unique-styled music, and as is often the case in Star Wars, background characters like that often get love. There were Legends stories about him surviving past the events of ROTJ, but the only recent story to hint at that was the non-canonical LEGO Star Wars Holiday Special, which isn’t exactly strong evidence for his survival. But now we know for sure, and I think that’s pretty cool.