Elytra

[fiery shore]

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[drifting summit]

https://tenor.com/view/you-don't-invincible-omni-man-jk-simmons-that's-the-neat-thing-gif-4390372980992221432

Jokes aside, the model of elytra (when worn on a player/entity) unfortunately cannot be changed (without mods).

Best you can do is texture variants

[spice shard]

Do yk which mod

[drifting summit]

Something like "Entity Model Features" might work.
Never used it myself though.