The Mimiga Mask is a mask given to Quote in the Plantation in order to talk to other Mimiga and do the tasks for Momorin Sakamoto so she can build a Rocket. Quote has to temporarily give her the Booster module he has, and fetch the Sprinkler, and the Control Panel for her. When Quote talks to her after she finishes the rocket, he trades it back for the Booster. If the mask is not exchanged, and Quote enters the Last Cave, it will be much easier to navigate. It is possible to beat the game wearing it, changing some dialouge in the game, such as Misery saying "You look hilarious!" before the battle with her.
- In addition to some changed dialogue during the last few battles, some of the pictures in the credits will be changed to show Quote wearing the Mimiga Mask.
- Finishing Cave Story+ (PC) with the Mimiga Mask on any difficulty will give you the Mimiga Hero achievement.
- Although all the Mimiga in the Plantation see Quote as a Mimiga with the mask on, enemies will still attack him, implying that they can see through the disguise.
- On Halloween, the Mimiga mask becomes a carved pumpkin mask (3DSWare 2D+ version).
- If you talk to Professor Booster while wearing the mask (meaning you must jump over him in the Labyrinth and obtain the Booster V 2.0 so he will remain alive), he will mistake you for a Mimiga and apologize on behalf of the humans for destroying the island.