Answer:
Darth MaulRemember that part in Star Wars Episode I: The Phantom Menance where a young Obi-Wan Kenobi faces off against Darth Maul, ultimately besting him in combat with a light saber slash that severs him in half and sends him tumbling down an air shaft? There’s definitely no coming back from being severed in half and that was certainly the end of Darth Maul.
Except, it wasn’t. According to numerous supplemental but official Star Wars universe books and media, Darth Maul survived the encounter. While spin-off stories have had Darth Maul live on as a brain in a vat (Star Wars Tales #17), a cult leader (Star Wars Tales #9), the incarnation of the Darth-Maul-lives tale that really takes the case is the version presented in the computer animated series Star Wars: The Clone Wars.
In the Clone Wars version, we find out that at the last minute Darth Maul used the Force to pull himself into a vent within the air shaft, escaped to Lotho Minor, had his lower body rebuild with a cybernetic suit that resembled the body of a spider, and lived in a cave like a mad-man hermit for a decade until his brother came to find him.
We apologize for taking away the satisfaction of watching the bad guy get his due and fall to his death.
ref: How-to geek