Are there any alien species that were first mentioned in a book, comic, or other non-film source that were then used in a Star Wars film? By film here I mean the major "Episodes" not Clone Wars. My impression is that the Star Wars films have mostly ignore EU material..
On the contrary, the films have borrowed extensively from the EU/Legends over the years.
Regarding alien species:
- The Toong were introduced in the 1983 Lando Calrissian Adventures book series, and named in Star Wars Droids. Ben Quadrinaros, one of the podracers in The Phantom Menace, was identified in the Databank as a Toong.
- The Theelin were introduced in Dark Empire, a 1991 comic book. They were added to post-1997 releases of Return of the Jedi, and in Phantom Menace, as slaves of Jabba
- The Falleen were first introduced in the Shadows of the Empire series. A miniature of the Falleen Prince Xixor was used in the Mos Espa crowd scene in Phantom Menace, though whether this was intended as anything more than an easter egg is unknown; Falleen characters later appeared in The Clone Wars as members of the Black Sun