>>33784727Foongus and Amoonguss are based on those quintessential red mushrooms with white spots that the Mario mushrooms are also based on. These mushrooms were used frequently in certain medieval fairy paintings because they are "magic mushrooms", being psychedelic and making those who ingest them feel either smaller (like a fairy,) or larger (Mario,) than they really are.
All that info had fallen into relative obscurity by the 20th century, but it was specifically Alice in Wonderland that brought magic size-altering mushrooms back into popular culture.
So yeah. Amoonguss.