It's called Coca-Cola 2nd Lives, and it's a genuinely and non-sarcastically ingenious campaign currently in Vietnam that allows empty Coca-Cola bottles to be used again by the distribution of 16 different caps that in turn provide 2nd lives to the bottles. Just pony up four regular Coca-Cola bottle caps and the kit is yours.
Oh, and then there's also a water gun, soap bubble wand, kid paint brushes, pencil sharpener, and totally indefensibly, a baby rattle as seen up above.
To really get a sense of just how directly this targets Vietnamese children, watch Coca-Cola's own promotional video:
[On the off chance I have readers in Vietnam, I sure would love a set of these for my collection]