Just a heads up, on Crystal Isle, only three wild tropes can spawn at any given time. There will only be one per biome; the tropical, ember, and jungle biome are where they spawn. They spawn mid-air and can either fall to the ground or stay flying where they spawned. They appear to not have a limit to how high they go. This is all for official spawns. It’s day 4 of writing this and I’m still looking. Also for private servers, tropes will take ages to respawn, so give it like 30 minutes until they show up. Hope this helps.
Kill Tapejaras as it share its spawn with them. I killed a few Tappy then 3 of them spawn in a row. On Rag, they are found on long 25. Found two different spawn so far, near blue ob and above green ob, always on long 25.
The wiki claims only two spawn at a time. And they no longer reside on other maps with the release of crystal isles. They can, according to sources, be found within the Tropical and Ember wyvern areas. And supposedly along the southeast side of the map with the floating rocks. I never found one but maybe this info can help