Dromondar Beta was introduced via mention in 2017's Star Wars: The Last Jedi: Incredible Cross-Sections, written by Jason Fry as part of the Incredible Cross-Sections reference book series.
Behind the scenes
Dromondar Beta was introduced via mention in 2017's Star Wars: The Last Jedi: Incredible Cross-Sections, written by Jason Fry as part of the Incredible Cross-Sections reference book series.
Sources
Star Wars: The Last Jedi: Incredible Cross-Sections