Bill Hargreaves served as a prop master, and he is the individual responsible for the creation of the IG-88, mynock, and probe droid puppets specifically for the film Star Wars: Episode V The Empire Strikes Back.
- A Star Wars Interviews page titled "Bill Hargreaves (Supervising Prop Maker)" can be found on the Wayback Machine. The original content is no longer available, but it was archived on December 9, 2022: link text
- The Fantha Tracks TV YouTube channel hosts an interview with Bill Hargreaves, uploaded on June 27, 2018 (backup link)