Jabba the Hutt was first mentioned in A New Hope when Greedo came to collect the money that Han owed Jabba, and we all know how that turned out. While a CGI Jabba was later added into A New Hope's 1997 Special Edition, he didn't make his true debut until Return of the Jedi, and it wasn't long before he was killed by Princess Leia during the Sarlacc sequence. Jabba briefly appeared in The Phantom Menace to watch the Podrace in Mos Espa, and he also made several appearances in Star Wars: The Clone Wars. Although specific plot details for the Han Solo movie haven't been revealed yet, Jabba's inclusion would make sense, as Han had performed several jobs for the Hutt before getting on his bad side. Since this movie takes place years before A New Hope, presumably it would either depict Han meeting Jabba or at least show the young smuggler at a time when he was still in good standing with the disgusting gangster.