first get a toadstool,then go to bart's exchangeand have himt turn the toadstool into a mushroom.(don't let your pinata eat them or they will get sick)PS:pinata's won't eat mushrooms.

to get mushrooms u have to plant toadstool seed in soil witha fence thats around them.... taaa dahhh u got mushrooms: ps u have to use bart befor the toadsstools are fully grown or it won't work