Do you know what a mushroom biome is?
...you do...I'll tell you anyways.

A place that has nothing but mushroom-related stuff.
The ground is made of mycyclium.
The 'trees' are giant mushrooms.
The animals are some sort of mutation cross between cow and mushroom.

Fun, right?

The animals are called Mooshrooms and only spawn in the mushroom biome. They are basically cows with spotted mushrooms on their backs and red and white coloring. You can use shears on them to get some spotted mushrooms and then they turn into normal cows.

When you milk them (with a bowl), you get mushroom stew!

It can be very hard to find (the biome, not the mooshroom!) and is not necessarily worth it in my opinion so here's a seed with a biome close by:

4

Have fun!!!!
O