This adult, gray, Tribble is from the 1990's Star Trek: Deep Space Nine episode 'Trials and Tribble-ations'. This Tribble was acquired directly from the award winning writer David Gerrold who wrote the original series Tribble episode and made a cameo appearance in the DS9 episode.
A screen-cap from the episode is included to both show this type of Tribble being used and to show David Gerrold as an red-shirt on the Enterprise.
