U can find the mushrooms very easy on the same place u find the blood wyverns. U can pick with your hand in the little mushrooms on the grass. U can find the featherlight on the northest but it have a little life and the region is very dangerous, so pay attention, probably It will die by something (like a rex, carno...). Will be good if u lock the featherlight in rock structures, then any dinos (that spawn there) can kill it while u tame.
If you want one of these, be prepared. They exist in areas around the Spine and beyond. There are Seekers, there are Nameless. If these don’t get you, then the Reaper Queen will surely get you. Not recommended for solo players who aren’t prepared for the worst. Bring your best and be prepared for anything. Zip lines, charge lanterns and batteries, light Dinos, guns. You name it, and it’s recommended to bring.
Just don’t bring your battle Bulbdog. I still mourn the loss of Pugbert. RIP