To ride a Happy Ghast, you first need to craft and equip a Harness.
In OjiCra, I crafted a white Harness and then tested how to ascend, descend, and dismount while flying above the castle town.
This article separates the official Minecraft Java Edition 1.21.6 mechanics from the controls I confirmed during that flight.
A Happy Ghast Needs a Harness Before You Can Ride
The official Minecraft Java Edition 1.21.6 release notes describe the Harness as an item that can be equipped on a Happy Ghast to let players ride it.
I also confirmed that I could not mount the Happy Ghast before fitting the Harness.
The first step, then, is to craft one at a crafting table.
How to Craft a White Harness
You need three types of material for a white Harness:
- 3 Leather
- 2 Glass blocks
- 1 White Wool
Place the three Leather across the top row of the crafting grid. Put one Glass block on each side of the middle row, with the White Wool in the center.
I used these materials to craft a white Harness in the OjiCra world.

According to the official release notes, the Harness takes the color of the Wool used to craft it, and there are 16 colors available.
I chose white to match Shiro, my white Happy Ghast.
Equip the Harness and Mount the Happy Ghast
Hold the crafted Harness and use it on the Happy Ghast to equip it.

Once the straps and fittings appear around its body, the Happy Ghast is ready to ride.
I looked up at it, interacted, and climbed onto its back.

The ascending, descending, and dismounting steps below are the controls I tested in Minecraft Java Edition 1.21.6.
Press Jump to Ascend
Pressing jump while mounted made the Happy Ghast rise.
When I faced the direction I wanted to travel and moved forward, it slowly flew that way.

The buildings below quickly became small, so rising a little at a time made it easier to judge the height.
Look Down and Move Forward to Descend
To descend, I looked downward and continued moving forward.
The Happy Ghast moved ahead while gradually losing height.

Starting the descent early and watching the intended landing area made returning easier.
Press Sneak to Dismount and Stand on Its Back
Use sneak to dismount.
The official release notes also state that pressing sneak dismounts a player on top of the Happy Ghast.
When I tried it in midair, I did not immediately fall to the ground. Instead, I found myself standing on the Happy Ghast’s back.

The Java Edition 1.21.6 release notes also explain that a Happy Ghast stops moving when it detects players standing on top of it.
Even so, it is sensible to check your surroundings and footing before dismounting at a great height.
Happy Ghast Riding Steps
Here is the full sequence I confirmed:
- Craft a Harness with 3 Leather, 2 Glass blocks, and 1 Wool
- Equip the Harness on the Happy Ghast
- Mount the Happy Ghast
- Press jump to ascend
- Look downward and move forward to descend
- Press sneak to dismount and stand on its back
The story of turning a Dried Ghast into a Ghastling is in OjiCra Season 3 Episode 41 (Japanese).
The full story of raising the Happy Ghast, crafting its Harness, and taking our first flight is in OjiCra Season 3 Episode 42.
You can find more hands-on notes in the Minecraft Memo archive.