What creatures drop COTO’s?

Perhaps all they did was added a 100x multiplier to the drop amount. But that also means you're more likely to get something rather than nothing now.

Previous to the 100:1 split, the drop amount was likely a fractional amount that started from zero (to some max, perhaps 2-3). So in the past, you could have gotten 0.15 COTOs for example, which resulted in nothing if less than 1.0. But with 100x multiplier, you're now getting 15 COTOs.