https://www.polygon.com/2018/10/18/17995380/super-mario-odyssey-zombie-mario-costume

A grisly new costume is available in Super Mario Odyssey just in time for Halloween: Zombie Mario.

Nintendo released a free update for the Switch game this week, adding the Zombie Headwear and Zombie Outfit to Super Mario Odyssey’s Crazy Cap shops. The headgear and outfit cost 3,000 and 5,000 coins, respectively, and can only be unlocked after completing the main story.