Hold on to your hats, your amiibo collection is about to get more complicated. GAF user L~A unearthed these two gems on Nintendo's own site.
In the thread, L~A posted two PDFs that appear to be regulatory paperwork. The two PDFs were hosted directly on Nintendo's site, and a number of commenters claim to have seen them. The going theory is these may be Club Nintendo rewards, though that doesn't seem likely.
What do you think? Is Nintendo going to release a limited set of Mario amiibos? Are they already sold out? Who am I kidding? Of course they are! If you want to see the full PDFs, hit the link above.