So supposedly no Pokemon is evil, yet it seems that quite a few Pokemon out there have no qualms against hurting humans in various ways. Hell, the Chandelure line will drain your life force, steal your soul and kill it with fire! Kyurem was rumored to eat people. Hypno...actually, let's not go there.
Anyways, what Pokemon strike you as the most notable in their eagerness to harm humans? You don't have to just go by the Pokedex and the main games, you can also cite other media, like the anime, the manga etc.
Shedinja apparently makes anything that looks at its back an empty shell, which includes the trainer using it. --- Not changing this sig until The Undertaker vs. Chris Jericho happens on PPV (started October 4, 2009)
IIRC, isn't the only reference to "no Pokemon being evil" just something that a random NPC said? Possibly preceded by an "I think"? I don't remember it ever being stated by the developers, or even said in-game without it being worded as opinion. Basically, it's about as true as shorts being comfortable and easy to wear (and they aren't!).
That said, in the first episode of the anime, Ash nearly relives a scene from The Birds, compliments of Spearow. I might remember that wrong. XD
Well, Pokemon are basically animals with a few exceptions, so of course some of them might attack humans. It doesn't make them "evil" any more than a wild tiger mauling a human is.
Anyway, to answer your question I would definately say that creatures as wild as Primape or Tyranitar are most likely to attack humans. --- "Why create when it will only be destroyed? Why cling to life, knowing that you have to die? None of it will have meant anything once you do." ~Kefka