Their natural form was that of small, winged humanoids. Their shapeshifting abilities were extensive, and they could transform into immense or tiny creatures. However, in order to change shape, a Gupin needed other people to envision the shape it would assume. Through telepathy, the Gupin could read their minds to shape his or her body accordingly.
Their homeworld was a mystery to the galaxy at large, but Professor Mankuskett believed their shapeshifting had evolved in response to "extreme environmental stress." A group of them were captured aboard the Starhunter Dhelba, which crashed on Endor, where the Gupins aboard established a colony in a large volcano in the grasslands near the edge of the Desert of Salma.
- Ewoks—"To Save Deej" (First appearance)
- Ewoks—"The Land of the Gupins"
- The New Jedi Order: Traitor (Mentioned only)
- The Essential Guide to Characters
- A Guide to the Star Wars Universe, Second Edition, Revised and Expanded
- Star Wars Encyclopedia
- The Official Star Wars Fact File 1 (WIC2, Wicket W. Warrick)
- The Complete Star Wars Encyclopedia
- Star Wars Galaxy Series 4 (Card: Amy Pronovost sketch card)