How to get, grow and ride a Happy Ghast in Minecraft
You hatch it from a Dried Ghast block, raise the baby, then put a harness on it to fly with up to three friends.

Harness lets players ride a Happy Ghast, in 16 colors.
It is made with the Crafting Table from White Wool, 2 × Glass and 3 × Leather (other recipes also exist).
Craft it from three Leather over two Glass with a block of wool between them; the wool color sets the harness color, and a dye changes it later. Use the harness on an adult happy ghast to put it on, and Shears to remove it.
Once harnessed, the happy ghast can carry up to four players and flies where its rider looks. It is the way to travel through the sky with friends.
White Dye + Any of #Orange Harness, Magenta Harness → White Harness
3 × Leather + 2 × Glass + White Wool → White Harness
// Slots with several items cycle through every accepted option.
You hatch it from a Dried Ghast block, raise the baby, then put a harness on it to fly with up to three friends.
At the Crafting Table: 1 × White Wool, 2 × Glass and 3 × Leather give 1 × Harness.
It turns a happy ghast into a flying mount for up to four players. Worn by: Happy Ghast.
No: only one per inventory slot.