Pokemon tend to follow a simple set of expectancies. Wild ones avoid or surprise trainersm, and have a chance of being caught. Caught pokemon follow the whims of their trainer and work under them. Pokemon gain power as they are trained.
Meulen is not the typical Pokemon however.
In Alola, Pokemon have adapted to their surroundings and circumstances and thus gained new forms. Meulen is an Alolan Meowth that has adapted to slightly differnet circumstances. He has alwayys been around people, trainers and what not, even though he is technically wide. Technically in a sense that he was 'owned' by a perculiar trainer, but not actually caught. In that trainers hands he was quite pampered, and not just by the trainer, but every one the trainer knew. It was like the Meowth was royalty as much as his trainer was. Eventually this developed behavior and ability in Meulen to adapt to a pampered life.
So when his trainer had gone on a trip or some such, the meowth took roads to being pampered by others. He is of the mind he always gets what he wants. To make it happen, he has developed slight psychic powers in his adaptation, making him able to control people suiubtly through soft gestures and such. His power over people and Pokemon alike isn't strong, but it always exists. This has lead to making Meulen a slightly dangerous Meowth to be around, and although predators exist and are adapting to counter the adaption of prey species, Meulen never realy adapted in the same manner.