As much as I joke about pokémon being highly dangerous, in actuality … all of them do have the potential for being highly dangerous to humans. All of them. Even magikarp, anonymous. Keep in mind that all pokémon have the ability to wield the elements of nature itself (although as I’ve mentioned in an earlier post, only legendaries can bend reality to do so), and for the most part, the only reason why they haven’t yet used those powers to kill off our entire kind is because they like us far too much to do so.
However, this doesn’t necessarily mean they are dangerous, especially when tamed. In the hands of a capable trainer, a pokémon as seemingly hazardous as toxicroak—or worse, muk or weezing—can become fairly harmless. I would still not be as audacious enough as to hug any of these pokémon, of course, but it’s very unlikely that one would lash out at a human and make a conscious effort to harm them if trained well. (Granted, there is absolutely such a thing as a disobedient pokémon, but a disobedient pokémon is vastly different from a vicious one. Even if a charizard turns its Flamethrower on its trainer, it never really aims to kill. Should anyone be curious as to why that is, ask yourselves whether or not you, as a current or former rebellious teen, would actually want to do serious harm to the figures of responsibility in your life.)
In short, certainly all pokémon have the potential to be dangerous in the wild, but that goes without saying. Once in the hands of a trainer, they’re much, much safer, and there really aren’t any regulations on what you can and cannot train. Obviously, however, it’s highly discouraged that one trains a pokémon far beyond their capabilities. For example, it’s not a particularly good idea to train a tyranitar if you’re starting out unless that tyranitar has been with your family for a while, simply because the trainer may not understand how to handle that sort of power. However, that’s why new trainers are typically given more docile pokémon to handle, usually the first stage in an evolutionary line, and that’s why trainers are often encouraged to stick to parts of a route that harbor pokémon that match their skill levels.
Rather, in even shorter terms, no, there are no regulations for what species you can and cannot train. So long as you catch them legally (as opposed to poaching them or catching ones from a preserve) and so long as you treat them well, all of them are fine to handle, as all of them, with proper training, are perfectly safe, regardless of how dangerous their wild counterparts are.
Or, well, almost all of them. Honestly, just about the only pokémon you can’t train (other than one that doesn’t wish to be trained in the first place) would likely be the legendaries, but that’s largely because catching them is considered to be a cultural taboo unless you happen to be an incredibly strong trainer. This goes especially for the cornerstones of a region’s culture. For example, it’s unlikely that anyone would mind if you caught Latias, but from what my editor has told me, it would be considered impolite to catch Rayquaza.
“Impolite.” That’s … that’s a great way of putting that, Bill. So I suppose this would mean that it would be “impolite” to catch Ho-oh? —LH
Oh, downright rude. The kimono girls would be absolutely chafed if you even tried. —Bill