DNA sequencing suggests that Foongus might be a Unovan variant of Morelull. The Pokémon adapted to live in urban environments, luring Trainers rather than Pokémon. Trainers who fall for this ruse and get knocked unconscious find themselves missing their Poké Puffs.

Amoonguss generally do not realize their disguise no longer works after evolution. Trainers who refuse to fall for Amoonguss’ obvious ruse find themselves being chased down by the Pokémon and its poisonous spores, offended by the insult.