The Thoughtless, especially since by their nature they aren't aware of what they're doing.
Compounded in-universe when Gancena sees one looking like Giygas, the Eldritch Abomination from EarthBound. And this was just an offshoot.
In Pokemon Tower, it's revealed that the Thoughtless can possess humans and Pokemon. One Rocket attacks Red's Pikachu physically, and almost does the same to Ash.
