The poison mushroom is an item that you can use when creating courses in Super Mario Maker 2. Those who played through the story mode of the game will recognize it and its unique features. The poison mushroom might look like an uglier version of the normal mushroom, but these things are deadly. They will follow you around the map and you cannot kill them with standard methods.
This mechanic does make for some interesting variety in your course, so here’s how to unlock the Poison Mushroom in Mario Maker 2 Course Maker. This is a two-step process and it can only be used on certain game styles. The poison mushroom can be used on all game styles except for Super Mario 3D Land, because you need to make the course night time. If you missed our guide on that, you can check it out here.
To make it night time you can do so by adding the Angry Sun to the map and then editing it into the moon. This will change your course from day to night. Once you have the map on night time, you will have the poison mushroom as an option to select from in the items tab of the Maker Menus. It’ll be found near the other power-ups (Star, Mushroom, Flower, etc).
Now that you’ve added the “Poison” Rotten Mushroom you need to know what it does. If you didn’t see it and get familiar with it in Story Mode, it’s basically an enemy type. The Rotten Mushroom will follow you around the map and it will kill you if you touch it. You cannot jump on it from the top, you also cannot kill it by attacking from below. You cannot defeat the Rotten Mushroom with Fireballs either. The ways to defeat the Rotten Poison Mushroom are to use Star Power or Yoshi can eat the Mushroom and spit it back out. The Mushroom will follow you most places, but you can avoid them if you can jump to higher ground.