Too Long; Didn't Read
Here is a list of the best Minecraft dragon mods:
Ice and Fire: Dragons (3 types of dragons plus other fantasy creatures),
Wyrmroost (many types of dragons useful for specific things!),
DragonRealm, (action-focused with special abilities),
Dragon Mounts: Legacy (various neutral dragons focused on exploration!),
Dragon Survival (play as a dragon! 3 different types! also has its own official modpack called Dragon Survival: Young Modpack!)