OK, this is weird. Daren Hinton posted photos of this vintage Kenner Canadian Nien Nunb action figure cardback from 1983, featuring a mailaway offer for a Nien Nunb figure! The pictures, posted in the Vintage Star Wars Cardboard Facebook group, shows an oddity most collectors were unaware of - an action figure offering itself as a free mailaway! That's some limbo-level inception stuff going on there.
When Nien Nunb was originally offered as a free figure mailaway to U.S. collectors, it was early in 1983, and the offer was included on the first wave of Return of the Jedi action figures. By the time the offer hit Canada later that year, however, the figure was already out on a card. That meant Canadian cardbacks with the offer were printed on all the figures available at the time, including Nunb. Here's a photo of the Canadian Nunb cardback with the offer:
Hinton and other collectors say that when Canadians sent away for Nien Nunb, they actually received the figure on the card, instead of loose in the white mailer box U.S. collectors received. Hinton believes this card was one of those sent out as a mailaway, as it is folded into fours to fix in a mailer. Now, here's the trippy part: someone clipped the proof of purchase from this card to redeem the free figure. So, Canadian collectors were able to use their free mailaway figure to collect a proof of purchase for another free mailaway figure. My head hurts.