If you use a spawn egg that has custom minecraft:entity_data set, usually it will summon a mob with that entity data. However, if you use the spawn egg on an adult mob, it will just spawn the baby variant of that mob without any of the custom entity data.
To reproduce
Give yourself a spawn egg with custom NBT:
/give @s minecraft:sheep_spawn_egg[minecraft:entity_data={id:"minecraft:sheep",CustomNameVisible:1b,CustomName:'{"text":"jeb_"}'}]Use the spawn egg on a block. This will summon a sheep named "jeb_"
Use the spawn egg while looking at the sheep you just summoned
Observed behaviour
A new baby sheep is summoned. The baby sheep does not have a custom name.
Expected behaviour
A new baby sheep is summoned. The baby sheep is named "jeb_".
Linked issues
is duplicated by 7
MC-260710
Spawn Egg with EntityTag can't summon mob with NBT correctly in some cases
Resolved
MC-276521
Piglins and Hoglins that are unable to Zombify don't pass on the NBT tag to babies
Resolved
MC-272659
Entity data is no longer applied to baby mobs spawned by using a spawn egg on an adult mob
Resolved
MC-208731
After obtaining a spawn egg for piglins that shouldn't zombify, placing the first piglin works as intended. But when placing the egg on another piglin to create a baby piglin, the piglin will become a zombie piglin if this happens in the overworld.
Resolved
MC-302262
Spawn eggs don't retain entity_data when used inside an existing mob
Resolved
relates to 2
Attachments
Comments 12
I think it's fixed in 1.10. I tried using a husk spawn egg with a command and any baby zombies are spawned as baby husks.
Can confirm in 1.18.1. Executing the Command provided below to reproduce.
/give @s minecraft:sheep_spawn_egg{EntityTag:{CustomName:'{"text":"jeb_"}'}} 1
It's more than that actually: the entirety of
EntityTagis ignored.