Throughout neopets you will be able to buy and even find some mushrooms. Depending on the kind of the mushroom, you may get good or bad results from feeding it to your pet. Here is a list of results from each mushroom.

Bad toadstool This will make your pet ill and will lose some hp!
Bloatershroom This is used to feed your pet!
Blood mushroom This is used to feed your pet!
Blue health mush room This mushroom will raise a neopets HP by one!
Flaky mushroom This is used to feed your pet!
Floatyshrrom This is used to feed your pet!
Green health mushroom This mushroom heals your pet!
Green toadstool Raise’s hit points by 3 and completely heals
Level up shroom This is used to raise the level of your pet by one!
Mega power plusshroom Increases the power and level of your petby one!
Pink toadstool This feeds you pet!
Poisionous Mushroom This mushroom gives your neopets neopox!
Propellorshrrom This is used to feed your pet!
Smellyshroom This is used to feed your pet!
Spindly mushrooms This is used to feed your pet!
Strength mushroom This raise the strength of your pet by 1,2 or 3!
Super fast shroom This shroom increases the speed of your pet by 1
Tealshroom This is used to feed your pet
Ugly mushroom This is used to feed your pet
Yellow mushroom This completely restores your pet!