Kids love soda, and kids love dolls. Uh oh... I feel some synergy coming on! Mattel had been chugging out the impossibly proportioned pulchritude of Barbie for nearly ten years by the time Liddle Kiddles hit the scene at your local toy shop in 1966. Though there were several versions throughout the life of the doll line (existing in some fashion or form through 1970) they were always characterized as being very tiny with a massive puzzler perched on top. Kleo here is about 2 1/2 inches tall, but there were versions ranging from 3 1/2 inches to just under 1 inch.
The dolls aren't that remarkable. Wait, I take that back - they are remarkably weird looking. Their bodies are made of floppy rubber, so they don't stand on their own; a task that's difficult at best, thanks to the "encephalitic cutie" aesthetic that still pervades (Bratz, I'm looking at you...) . I shouldn't make such a big deal about the proportions - there is a long rich history of this sort of distorted caricature. How Betty Boop ever stood upright with that giant melon of hers I'll never know. For what it's worth, I have the same doubt of Barbie's ability to stand up, but for a different reason(s).
Back to Little Kiddles, Mattel had learned a valuable lesson from Barbie; namely the value of offering a giant selection of accessories. Kiddles didn't just come in soda bottles like Kleo. There were Kiddle sized cars, vinyl houses, even tiny UFOs for the alien based characters (which I hate to admit I'd love to find someday). There were a few human sized add-ons too; records, books, even accessories so you could wear your Kiddle like jewelry. Mattel was ready for a big hit, with the Kiddles resisted at every turn.
With a novelty vibe firmly established, it's still a little unusual that these dolls come to you in a replica cola bottle. It's not quite the mystery of a ship in a bottle, but it doesn't really fit in with the rest of the toy line. There were many flavors of doll, strawberry, grape (complete with grapes in her hair) and cola like this one. Sadly Mattel hadn't thought to embedding a soda-like stink into the dolls like stinky Strawberry Shortcake years later.
There's also no backstory or anything about the dolls having been born in a bottle, or accidentally delivered by a magic soda jerk... No carbonated crib, or other soft drink outfits. Just a novel outcropping of an otherwise not too remarkable line of dolls that fall over. Despite the short life of Liddle Kiddles, there was a pretty big variety - but nothing compared to Mattel's other stablemate Barbie. There just wasn't room for Kiddles in the toy aisle, or your grocery store's soda aisle.