Star Wars: The Rise of Skywalker had a blink-and-you'll-miss-it cameo from one of Darth Vader's old bounty hunters. Star Wars fans have always been fascinated by the galaxy's seedy underbelly, and as a result Lucasfilm has happily fleshed out secondary character ranging from spice smugglers to bounty hunters.
One key scene sees Rey and her friends head to the ice-world of Kijimi in order to meet Babu Frik, who they hope can hack C-3PO's programming. Once famed as a world of marked spirituality, Kijimi has become a haven for bounty hunters and criminals due to its distance from the Galactic Core. The group have to make their way through a bar in order to get to Babu Frik's workshop - and that's the perfect opportunity for director J.J. Abrams to slip in a cameo.
One of the figures standing at the bar is a tall, black-armored figure with a cybernetic arm. According to the Star Wars: The Rise of Skywalker Visual Dictionary, this is Rothgar Deng, an old and experienced Corellian bounty hunter. Age has slowed Rothgar Deng's reflexes, and as a result he's turned to black-market surgical clinics to replace damaged or wizened body parts. Unfortunately, poor decision-making has led to a pretty ghastly appearance, and frankly it doesn't look as though the cybernetic replacements have given him the edge he hoped for. Significantly, the Visual Dictionary stresses that "Rothgar Deng" is an alias - and it's not hard to figure out who he really is. He must be Dengar.
Dengar is a Corellian bounty hunter who was introduced in The Empire Strikes Back and who played a prominent role in an arc of The Clone Wars animated series. Never particularly bright, Dengar has always had a "shoot first and ask questions later" approach to bounty hunting, which means he tends to run into a firefight. Chuck Wendig's Aftermath trilogy confirmed that he remained active as a bounty hunter even after the fall of the Empire, and it seems that he's still active by the time of the sequel trilogy. Unfortunately, by this point he's getting too old for such a high-risk profession, and his body is suffering for it.
This may be the end of Dengar. Discovering Rey and her friends are on Kijimi, the First Order places the entire planet under lockdown. Later, one of Palpatine's Death Star Destroyers blows it up, demonstrating the firepower that the returning Emperor has at his disposal. While Zorii Bliss and Babu Frik manage to steal offworld, it's unlikely that Dengar had the same good luck.