I found a bug on the elytra they have the texture of a ressource pack.

What actually happened was...:
I wented to try all the carpet of the game on a Llama

I did not found another who talk about the same bug but I found another one who talk about elytra.

Steps to Reproduce:
1. take in your inventory all the carpet of the game x64 (I have upload a
picture to show you)
2. take an elytra
3. put them on you
4. F5

Sorry for my english, I hope to be useful for your development!