Monster Hunter World - Snuggles for All Trophy / Achievement Guide - Capture a fluffy, snuggly creature. [Silver / 30G]

For this trophy / achievement you must catch a tiny white bird called "Downy Crake". It only spawns on the backs of Aptonoths in Ancient Forest and on the backs of Apceros in Wildspire Desert (those are the friendly dinosaur monsters). It can spawn at any time of day and on any rank (low-rank & high-rank).
To catch the fluffy bird you HAVE TO be wearing the Ghillie Mantle. Otherwise the bird will fly away and you won't be able to catch it. The Ghillie Mantle is unlocked automatically in the story. You can equip it at the item box in Astera or at any camp.

To see the exact spawn locations and what the creature looks like, check the video. I recommend that you fast travel between the Ancient Forest and Wildspire Desert. At the first camp of each area are the required monsters that can spawn the bird on their back. If it's not there, immediately fast travel to the other map and keep doing this over and over again. It took me 2 hours to find the birds, they are ultra rare (1% spawn chance at best).
With the Ghillie Mantle they can't see you. Run up to the dinosaur and use the capture net to catch one of the birds off the dinosaur's back. You can also hear a chirping sound when the birds are nearby so listen carefully.