HappyGhast+ is a datapack/mod that lets you customize the Happy Ghast, like flying speed and resistance.
You can open the Settings menu with the command "/function happy:settings".

Adjust the Happy Ghast's flying speed from Standard up to +200%. Each setting can also be set to Enchantment mode, where the speed is determined by the Propeller enchantment on the harness instead.
Set the Happy Ghast's resistance from Disabled up to Invincible. Can also be set to Enchantment mode, where the resistance is determined by the Resistance enchantment on the harness instead.
Prevents the Happy Ghast from moving when no player is riding it. Can be set to Enchantment mode, where the Anchor enchantment on the harness controls this behavior.
Controls whether Enchantment books can be found in chests. Useful for server owners who want to control the distribution of enchantments themselves, for example through custom shops or events.
Three new harness enchantments: