Boba Fett's reputation in pop culture sprouted out of very little information. With few lines in the Star Wars films in which he appears, most of Boba's cool factor came out of his unique look and a single line of dialogue "No disintegrations," Darth Vader warned him while instructing a group of bounty hunters in 1980's The Empire Strikes Back tasked with finding the Millennium Falcon. However, it wasn't until decades later that fans would learn the reason behind the Sith Lord's very specific prohibition.
Without any other information about him to go off of, the line deftly clued audiences into Boba Fett's reputation as a merciless killer. The line also establishes the bounty hunter has a history with Vader, hinting that the bounty hunter career has a history behind it to support his reputation. Given how unforgiving the audience knows Vader to be, there must be no questions about Boba's effectiveness given the Sith Lord allowed him to live after the previous blunder.
It's in the series From A Certain Point of View that the Star Wars canon first addressed what disintegrations Vader was referring to. The anthology presents various short stories from the perspective of several characters throughout the original Star Wars films, many of whom received next to no dialogue in the films proper. Within From A Certain Point of View was a story by Paul Dini, Added Muscle, which served as the perfect staging ground for fans to gain a brief peek into Boba's mind.
Though Dini is best known for his work on Batman: The Animated Series, he still brings his unique knack for quickly encapsulating a character to the Boba Fett short story. Taking place on Tatooine during the events of A New Hope, Dini characterizes Boba as much more of a thuggish criminal than the original series ever had space to convey. Overseeing Jabba's negotiations with Han Solo, Boba reflects on his previous mixup with Vader involving the disintegrations.
"He's [Vader] still got a mad on over those rebel spies I crisped on Coruscant," Boba reflects. "Idiots came at me with ion disruptors. What, they thought I wouldn't carry a weapon accelerator? Flash, boom, three tiny ash piles." Unfortunately for Boba's wallet, Vader refused to pay the bounty without any bodies for Boba to present as proof. Boba took it as a personal slight, and the lost bounty serves as the impetus for him hanging around Tatooine an extra day to try to find the droids the Empire is looking for.
The moment comes as a really cool insight into Boba's mind. Although fans of Star Wars: The Clone Wars are well-familiar with Boba's characterization as a teenager, eagerly learning the ropes of bounty hunting at the start of his career, Added Muscle offers a chance to see how his attitudes evolved into adulthood.