Four con artists made their appearance in "The Poké Spokesman" (EP197) as the episode's main villains. They'd been running a Pokémon interpreter scam, pocketing money from fake translation services until Officer Jenny got wind of it. When the police started closing in, they accidentally targeted Simon—an actual interpreter who happened to match the description from the report—and nearly arrested him before the scammers made their move. They fired missiles to blind everyone, then kidnapped Simon, convinced he was a fraud like them and hoping to recruit him. Simon wanted no part of it though, and managed to escape.
Later at the Pokémon Center, the gang showed up again with their Magnemite and Magneton, this time trying to extort the place by having their Pokémon drain the building's power supply. Nurse Joy couldn't get through to them, but Simon's actual ability to communicate with Pokémon worked where pleading didn't—he got the Magnemite and Magneton to stand down. When the leader got angry and kicked his own Magnemite, it backfired spectacularly. Pikachu hit both Pokémon with an Electric attack that left them fired up and ready to turn on their Trainers. The four con artists were arrested shortly after.
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