There are already so many big mystery mushroom characters in Super Mario Maker that can be unlocked, but still Nintendo constantly insists on presenting us with even more as a reward for specific course completion. The latest reveals for upcoming mystery mushrooms in Super Mario Maker include Captain Toad, Birdo, as well as Excitebike. The Captain Toad costume will become available on December 25th, whereas the Birdo and Excitebike costumes will arrive on December 31st. Just remember you will need to beat the specific course event in order to unlock the costume.