Amoonguss is a mushroom-like Pokémon with a large, light-colored Poké Ball designed cap with warts. It also has a huge grayish, stem-liked body, fierce looking eyes and a large pink mouth. Amoonguss wields two Poké Ball-like shields. It uses the Poké Ball-like patterns on its arms to lure in prey, though it doesn't work too well in most cases. Amoonguss is a carnivore which can be found mainly in long grass, as only their mushroom cap head protrudes from it, generally close to water.
Amoonguss, the Mushroom Pokémon and the evolved form of Foongus. By swinging its Poké Ball-like arms while dancing, Amoonguss is able to lure its prey.
In the manga
Amoonguss in Pokémon Adventures
In the Pokémon Adventures manga
Bronius owns an Amoonguss where he used it to put Bianca to sleep with Spore. It had a battle with Black's Pignite, Nite, and lost due to the double type-disadvantage.
Amoonguss, along with its pre-evolution, is similar to Voltorb and Electrode in that it resembles a Poké Ball.
However, unlike Voltorb and Electrode, it only has a Poké Ball design on it, instead of being in the shape of one.
Likewise, it features the whole design, complete with the circle resembling the button in the middle (contrary to Voltorb's evolution line having just the shape and general colors, and according to the Pokédex, being transformed Poké Balls themselves).
Amoonguss has the highest HP base stat among all Poison-type Pokémon.
Amoonguss is the only Pokémon with a base stat total of 464.
Origin
It appears to be based on Amanita muscaria or mushrooms of the Agaricus genus, due to it being Poison-type. Its cap and the shield-like arms were designed to look like the front of a Poké Ball.
Name origin
Amoonguss may be a combination of amanita (a genus of mushroom) and fungus or humongous (huge). Together with its evolution, their names are a corruption of the phrase, "Fungus among us."
Morobareru is a combination of もろ moro (on both sides, referring to the mushrooms on both hands) and ばれる bareru (slang for "to be found out" or "to come out").