This minecraft seed 4629091465175177150 features a huge mushroom biome, perhaps the largest I have seen in the game so far. It really is large, and worth checking out, tons of mooshrooms etc…
There is a surface dungeon in the desert at X:-279 Z: 604
Huge mushroom biome at X: -40 Z: 56
The minecraft seed i dont care spawns you on a large jungle biome island, a small part of which is a mushroom biome. There is a large mushroom biome next to the island as well. Tons of great scenery, lots of adventuring in the jungle biome and a steady food source from the mushroom biome. This is a great seed!