"They help take of the edge. They help you relax."
The Mushroom is an item you can buy from Rulio for a Shiny in Alice is Dead 3. It is a foul-smelling fungus that grows right out of the sidewalks in Wonderland City. Although supposedly a narcotic, it is also highly toxic and can be used to poison the drink near Tweedledee and Tweedledum, apparently causing Tweedledum's head to explode, killing them both.