Minecraft wiki entry for Skeleton, associated text: Skeletons spawn at a light level of 0 in groups of 4 or 5 in the Overworld in Java Edition and 1 to 2 in Bedrock Edition. They can be found above solid blocks from all Overworld biomes except mushroom fields and deep dark‌[upcoming: 1.19]. 80% of skeletons spawned directly under the sky spawn as strays in snowy plains, frozen oceans, and variants.