This mod applies a few patches to the excellent vanilla-friendly dragon mod Dragon Mounts: Legacy

Dragon Mounts: Legacy is a required dependency.

There are currently no plans to port to other versions besides 1.20.1 Forge.

Currently, this mod has the following features:

• Registers dragon egg variants dynamically in JEI, so you can see every type of dragon egg. (Fixes only the "Aether" or "Water" egg variant type being viewable)
• Fixes a crash when trying to use the commands keybind while not in-game. (Fixed in newer versions of the mod, but not in 1.20.1) 

Why not a PR?

The authors don't seem to be interested in maintaining older versions. I may submit the JEI integration as a PR for 1.21. The original author is also free to just copy it.