Fans learned in the classic Dark Horse comic series Dark Empire by Tom Veitch and Cam Kennedy that Fett’s armor allowed him to survive inside the sarlacc and fight his way out, blowing up the creature in the process. The novel The Mandalorian Armor by K.W. Jeter further explained that it was rival bounty hunter Dengar who had found Boba Fett half-dead in the desert and nursed him back to health.
From that point on, Fett became a regular character in the Legends expanded universe, featuring in many bounty-hunter focused books. He also made a brief cameo in the 19-book New Jedi Order series and appeared in the Jedi-focused Legacy of the Force and Fate of the Jedi books. In fact, Fett lived on until the very end of the Legends timeline, completely defying the odds after his initial demise in Return of the Jedi.
Boba Fett eventually became the leader of the Mandalorians, which had a sprawling culture and even their own official language in Legends. Fett had a family and his granddaughter ended up assisting in the training of Jaina Solo, Han and Leia’s daughter.
As in the Sequel Trilogy, Legends included the continuation of the Skywalker-Solo clan, and, while Fett mostly kept to himself as the leader of a third faction sometimes opposed and sometimes allied with the Republic, he was involved with incorporating Mandalorian fighting into Jaina’s Jedi training. He became a formal ally of the Jedi in the war against Jaina’s brother, Jacen Solo/Darth Caedus, in Legacy of the Force.
Will the Disney canon do something similar with Boba Fett’s post-Return of the Jedi story? Will his armor save him from the sarlacc once again? We don’t know what the studio might have in mind for Fett, and whether he will eventually turn into a more sympathetic anti-hero character, but it wouldn’t be surprising if some elements from his Legends storyline were brought into the new canon. That’s exactly what Disney did with Grand Admiral Thrawn, another character whose Legends story was pieced together in a new way on Rebels.