I've seen episodes with mycelium and mooshrooms... and I know that they're supposed to be vanilla. How did this happen? did they really find a mushroom biome?
They've found several. There's a rail line in their nether hub leading to one and more recently docm found the smallest one I've ever seen (it was like 8 blocks sticking out of the water) not too far from his jungle base. Also you could grow giant mushrooms on dirt until either 1.2 or 1.3 as long as there's room for them to grow.
How does the mindcrack server get mycelium & mooshrooms?