This mod adds a new type of mooshroom that spawns in mushroom biomes. They are just like regular muooshrooms except they are brown versions. Pictures are below.
1. Open the minecraft.jar with an extraction utility
2. Delete the META-INF folder inside the jar
3. Install modloader
4. Unzip the mod folder
5. Place all the files and folders from the mod folder in the minecraft.jar overwriting existing files
6. Run minecraft