There are a plethora of biomes in Minecraft, even when just analyzing the base versions. They range everywhere from beach and savannah to taiga forests and lush jungle. But there are plenty of smaller versions of those biomes that can be found in the overworld.
One of the most rare versions of the small biomes within the bases is the mushroom fields. They cover about 0.056% of the entire overworld in Minecraft, which is incredibly small. But there is one biome that is insanely rare, and covers even less than that of the mushroom fields. That biome is the modified jungle edge.
What is the rarest biome in Minecraft?
The modified jungle edge biome is the most rare biome in Minecraft as of now. While the mushroom fields cover 0.056% of the overworld, the modified jungled edge covers just 0.00027% according to the Minecraft Gamepedia. In order for the modified jungle edge to spawn, there are a few rare conditions that need intertwine with each other.
First, a swamp hills biome needs to spawn just outside of a jungle biome. When compared to the other base biomes in the game, both the swamp hills and the jungle are fairly rare biomes on their own. To find them together is an extremely rare case in Minecraft.
Once those two biomes spawn directly beside each other, a jungle edge will spawn between the biomes. The jungle edge is a transitional biome that is in place to make the overworld appear more natural. Rather than going from an incredibly dense and lush forest to a stark plains biome, there is a natural progression. In between the 2 biomes, some jungle trees will remain, but they will be spread out, and the colors of the 2 biomes will start to mend together until the biomes change.
In the modified jungle edge biome, there is a slight difference. With most jungle edges, the terrain is relatively flat and contains some jungle aspects. When it meets the swamp hills biome though, it creates a new edge effect. The area between the biomes becomes a bit mountainous, but also contains trees from the jungle.
This effect can't be found anywhere else in the overworld of Minecraft. On top of that, the modified jungle edge biomes can be incredibly small. At times, they can end up as just 10 blocks or smaller, and on average, they are just a few hundred to one thousand blocks in size.