The Passenger and Dr. Mandible were both previously seen in the Mos Eisley cantina in Chapter 5: The Gunslinger (2019).
The Passenger's froglike species is based on Gribbet, the Rybet bounty hunter, first seen in the Star Wars newspaper comic strip in 1981. A similar shaped alien is also visible in the illustrated backdrop that was part of the 1978 Cantina Adventure Set (Sears exclusive).
A large hairy Gigoran can be seen in the Mos Eisley cantina. This species was first seen on screen in the shape of one of Saw Gerrera's partisans named Moroff in Rogue One: A Star Wars Story (2016). However, the one seen here has the same Kessel mine spice stains in its fur as the Gigoran named Senna from Solo: A Star Wars Story (2018).
Peli remarks that she's "not some Rodian", referring to the green-skinned species with large pupil-less eyes which have popped up throughout the franchise. A number of Rodians worked as bounty hunters, like Greedo in Star Wars: Episode IV - A New Hope (1977).
Peli and Dr. Mandible are playing a game of Sabacc. This widely-popular game was first mentioned in Star Wars: Episode V - The Empire Strikes Back (1980), but it also appeared in Star Wars: Rebels (2014) and Star Wars: Episode VII - The Force Awakens (2015), and was heavily featured in Solo: A Star Wars Story (2018).