>>37445149The high level foe is possible but probably rare (in games, local trainers have mons similar in level to wild ones; in anime, most wild defeats are due to terrain or unfamiliarity rather than strength). There's likely at least one mon in most regions who fits this role, but probably not many. And in the anime, at least, Pokemon really don't have to stay in their balls; it's just often convenient. Croagunk reacted to Brock flirting, so it's definitely possible for a team to emerge to defend their human (unless the snake has the prescience and ability to somehow prevent the balls from opening).
Now of course, it's definitely possible for an Arbok to have the cruelty and cunning to effectively hunt humans. It probably just isn't too common.
I still think an Arbok's Relaxation Parlor thing would be pleasant. Even/especially without the vore trope of "it's like a full-body hug" as justification for swallowing your customers.