Rare mushrooms add 50 food per. Don't decay. Easy to get from megachelons. Rare flower work as well. Beware they starve extremely fast. So only food with high enough food value will keep them alive. Aka not the seeds u get from megachelons. That will cause them to starve faster than they can eat.
Very easy to raise, just drop tons of stone infront of the baby. It will keep picking up stones no matter what it's weight cap is.you can fill unlimited stones like this and will never have to hand feed.