Visual durability of elytra
More info - https://www.curseforge.com/minecraft/texture-packs/visual-durability-of-elytra
Textures of entities, blockes
Custom BossBar
Potions
Textures of blockes, dragon
Armor and books
Visual durability of shield
Cool Font
Visual ender pearl count
You can see how many ender pearls the enemy has.