My first exposure to this packaging style came via email years ago from a fellow collector that owned a rather peculiar carded Joker. At the time I didn't make the connection despite the small "Made in Australia" text being present, but the brain bulb lit up when I purchased this Batman from an Australian seller. My best theory at this time is that 12-Back were sold in Australia using this unique packaging prior to release of the 2nd series. In 1985 this packaging style was discontinued in favor of using Kenner Canada packaging tweaked for the Australian and New Zealand markets via the simple white sticker with black text discussed earlier.
So, what makes these Australian 12-Backs so special? While a number of unique characteristics are present, the "Collect Them All" banner in the card front's lower right corner stands out as the most interesting. The peg hole shape also stands out and is completely unique to this card style. The cardback also contains some interesting differences. The blue coloration is much darker than that found on US Kenner 12-Backs. The block situated to the left of the file card is dedicated strictly to advertising text as opposed to the vehicles and playsets shown on the US 12-Back "Fan Club Offer" packaging and graphic/text blends used on both the US 12-Back "Free Poster Offer" and "Steppenwolf Offer" packaging. The remaining detail of interest is found in small black text at the bottom indicating the carded figure was "Made in Australia".
These Australian 12-Back carded figures are extremely rare and rank comparable in scarcity to most carded figures on Lili Ledy and GMJ S.A. packaging. At the time of this entry I've only documented single examples of Batman, Joker, and Penguin, but surely additional examples and other 1st series characters are out there waiting to be uncovered.