BTCitcoin toys could have an impact on kids getting interested to BTCitcoin when they grew up and eventually be educated in some extent although not completely. Even though kids have undeveloped mindsets as you mentioned, it's our job to break it for them into simplest form so they would learn it piece from piece (the outcome could be better when they learn it like this all the way until their mature enough to understand the whole picture than when their grown up, you introduce them suddenly and surely their going to take more time before getting the idea completely as opposed to the first one).

If I wanted to invent a BTCitcoin toy, it has to have the full name of BTCitcoin in order to have some impact, so perhaps something along the super hero type with BTC letter as it's simple and name it BTCitcoin man or BTCitman. It's has to be a toy that kids would engage in order to have the most result.