complete.
The yellow crab (name is Sandclaw) appeared in 1134 - 1137
twice, I killed and nothing happened,
After 30 minutes, there was a small tornado (same place), I accompanied for about 7 meters (not clicked) and it disappeared,
I may have pressed the button "auto-loot" and did not even realize,
then I looked in my inventory, and i was with the feather.