A Ghastling grows into a much larger Happy Ghast over time.
In OjiCra, I named the Ghastling at the castle town fountain Shiro, fed it Snowballs, and watched it grow up.
This article separates the official Minecraft Java Edition 1.21.6 mechanics from the timing I observed in that session.
A Ghastling Grows into a Happy Ghast in About 20 Minutes
The official Minecraft Java Edition 1.21.6 release notes state that a Ghastling takes approximately 20 minutes to grow into an adult Happy Ghast.
The small white creature floating at the castle town fountain is the Ghastling before it grows up.
I named this Ghastling Shiro.
Without feeding it anything, the official guideline is to wait approximately 20 minutes for it to grow.
Snowballs Help a Ghastling Grow Faster
The official notes explain that feeding Snowballs to a Ghastling makes it grow into a Happy Ghast faster.
Snowballs can also be used to tempt a Ghastling, and you can feed them directly to it.
In OjiCra, I held a Snowball while facing Shiro beside the fountain.
Keeping Snowballs ready gives you a way to guide the Ghastling and help it grow sooner.
Shiro Grew Up in About 9 Minutes After 13 Snowballs
The timing in this section is an observation from this OjiCra session, not the general official growth time.
After naming the Ghastling Shiro, I fed it a total of 13 Snowballs.
About 9 minutes after naming it, Shiro grew into a large Happy Ghast.
The official growth time is approximately 20 minutes. My result of about 9 minutes applies only to this attempt, when I fed Shiro 13 Snowballs and watched it grow. It does not mean that 13 Snowballs will always produce the same 9-minute result.
Ghastling Growth Summary
For Minecraft Java Edition 1.21.6, the key points are:
- A Ghastling grows into a Happy Ghast in approximately 20 minutes
- Feeding Snowballs helps it grow faster
- Holding Snowballs tempts a Ghastling, and the Snowballs can also be fed to it
- In OjiCra, Shiro received 13 Snowballs and grew up about 9 minutes after being named
- The 9-minute result was specific to this session, not a general growth time
For the steps before this stage, see how to grow a Dried Ghast into a Ghastling.
Once the Happy Ghast has grown up, the Happy Ghast riding guide explains how to craft a Harness and control it in the air.
The full story of naming Shiro, feeding it Snowballs, and taking the first flight is in OjiCra Season 3 Episode 42.
You can find more hands-on guides in the Minecraft Memo archive.