When Sonic the Hedgehog and Miles "Tails" Prower arrived on Angel Island to investigate why it had begun to fly towards Knothole Village, the two were dropped off in Mushroom Zone where they were attacked by giant mushrooms and later Hei Hou. Some time later, Knuckles the Echidna and the Chaotix assembled in Mushroom Zone when observing the Death Egg approach the island. After a group of large Burrobots were dropped off there, the Chaotix worked together and destroyed them. (SQM: #1, #2, SaK)
- Mushroom Zone is based on the level Mushroom Hill Zone from the videogame Sonic & Knuckles.