How does one go about taking ownership of any of these other coins based on btc ownership at the time of that new coins creation and which are they?
Looking at CDY now. I see: In the case of CDY, holders of BCH will receive 1,000 CDY for every BCH they hold. WBTC, on the other hand, will airdrop 100 tokens for every BTC. It should also be noted, that Coinex is the only exchange currently trading CDY and thus if your tokens are not held in a BCH wallet, you may not be eligible to claim the hard fork. (from: https://cryptoticker.io/bitcoin-candy-world-bitcoin-mined/).
So, kind of the reverse of the bch fork, easier, eventually, if one had one's btc on Coinbase rather than in a private wallet. The CDY makes having the bch in a private wallet necessary to possibly 'be eligible to claim the hard fork'.
It would be nice to see CDY listed among CoinGecko's 1149 listed cryptocoins.