Baby villagers produced by right‑clicking an adult villager with a villager spawn egg do not use the biome of the block where the interaction occurs. Instead, the baby villager’s biome variant is determined by the biome located at the world origin (0, 0, 0). Changing the biome at world origin directly changes the variant of all baby villagers produced by spawn eggs, regardless of the biome the villager is standing in.
I performed additional testing and found that the incorrect villager variant is not random. The baby villager always uses the biome variant from the world origin (0, 0, 0) instead of the biome where the adult villager is located.
For example:
If the biome at (0,0,0) is savanna, all baby villagers spawn as savanna villagers, even in plains or forest biomes.
If I change the biome at (0,0,0) to jungle using
/fillbiome, all baby villagers spawn as jungle villagers, even when the adult villager is in a completely different biome.
This confirms that the spawn‑egg biome lookup is misrouted to world origin instead of using the villager’s actual position.
This behavior is 100% reproducible in affected worlds.
Environment
Minecraft Java Edition
Version: 26.1 snapshot 1
Singleplayer world
No mods, datapacks, or world editors
Issue persists across multiple biomes and distances
Reproducible in both new and existing worlds
The behavior I found may explain why MC‑305128 happens, but it is more specific than what that report describes. If this is considered a different issue, please let me know and I will create a separate bug report for it.