I remembered the other thing too. When Sirius decided to escape, he said that he was thin enough as a dog to pass between the bars. Now if I remember correctly there wasn't any other mention of security that gave him trouble as a dog, which leads us to think that Azkaban is mostly run by Dementors, with little to no human presence.
So, what was stopping Pettigrew from turning into a rat and just walking out? Maybe the security was tighter (because of X fact that was different than in cannon), which means that he wasn't able to turn into a rat, else he would have escaped. Lack of Animagus-resistance would lead to him becoming very crazy very soon.
But maybe crazy with a goal?

 

Security was definitely tighter. One passage says so, and also suggests that it was developed specifically for Pettigrew. He escaped due to a bureaucratic fuckup relaxing the wards.

 

My bad, my bad.
But still, that would lead to a bat-shit insane Pettigrew with a purpose. Like Pers so awesomely demonstrated.

 

Idk, honestly. Four in a century (registered) sounds very very rare for me.

 

Three in one year (unregistered) speaks differently.

 

Of which two are prodigies, who don't care for rules, and one is lucky to have clever friends. Still very very rare for me.

 

Don't know if I'd call them prodigies, but James' area of expertise was transfiguration. I imagine that would help them in their endeavor.

That being said, I imagine the skill isn't nearly as rare as the registration makes it seem. If bunch of kids can figure it out just to go screw around at night once a month, then it's likely that others have figured it out too.

 

I think it's less to with whether people can or can't learnt and more whether they'd want to. For most I would suspect that becoming an Animagus has little benefit and the Marauders only learned it for Lupin's sake.

 

For me it's seem more like MoM propaganda. The Ministry think, that they know every animagi. They can't comprehend that, someone can master the ability and don't register.
About relaxing the wards and joke that Fudge is animagus, well with Pettigrew and Skeeter being ones, all is possible but I highly doubt that

 

You have an extraordinarily loose definition of the word prodigy. Dumbledore is a prodigy. Voldemort is a prodigy. We don't see them inventing spells, or potions, or anything of the sort that would suggest they are prodigies. Dumbledore's accomplishments are legion, Voldemort pushed back the boundaries of magic, even Snape was inventing spells in Hogwarts. James and Sirius? Played pranks and stole Snape's spells.

James and Sirius are normal wizards, that canon suggests were above average. Other than the Marauders Map and the transformation (and really we have no idea how difficult either of those two things are) we have no real evidence to pinpoint there skill level. We never see James and Sirius scenes never really show any evidence to suggest that he's an extraordinary wizard.

You're also suffering from confirmation bias. James and Sirius are 'good' while Peter is 'eveil so you want the former to be prodigies while Peter was "lucky". Peter accomplished the same things that James and Sirius did. (Map and animagus) Not only that, Peter (in Canon) betrayed the Order and successfully hid that from everyone, including Dumbledore, a legilimens. That suggests he was a more than competent Occlumens. He also, on the fly, managed to ensure that he escaped, Sirius was caught and he killed 12 people at once. A prodigy? No. But not a snivelling incompetent lucky to have talented friends either.

tl;dr James and Sirius aren't prodigies and their Animagus accomplishment doesn't make it rare. Nor does the fact that they're "good" and Peter's "evil" make them great wizards and him incompetent.

 

Edit:

@Taure: Based on what do you say Bellatrix is talented? Her demise and her performance at the DoM indicate otherwise.

 

They're not prodigies, but they're more than "above average" I think. While the Animagus transformation and Marauder's map aren't on the same level as the accomplishments of other wizards, I think you're underestimating them somewhat.

If I had to make a scale of magic users, I think I'd do it something like this:

Prodigy (Dumbledore, Voldemort, Grindelwald).
Gifted (Snape, Lily, McGonagall).
Talented (Sirius, James, Bellatrix, Slughorn, Kingsley, Mad-Eye).
Highly competent (Hermione, Lupin, some Aurors).
Above Average (Arthur Weasley, Percy, sometimes Harry).
Average (Ron, most DA members).
Below average (average Ministry worker).
Bad (Lavender, etc.).
Near Squib (Early Neville).
Muggles and Squibs.

 

I disagree with a lot of that list, but I suppose it all comes down to how you decide to judge "magical users".

Anyway, this debate is quickly losing focus; in fact I can't even remember why we came to discuss the rarity of animagus transformations, never mind percieved ability of witches and wizards from what we know of canon.

 

I suppose that's as reasonable as any other list. My main point was that it's not possible to create a list of magic users in any sort of objective way. We simply don't see enough of the various people.

Just an example, using your list. How you can you possibly know that Lupin is less talented than Sirius and James? He helps them create the Marauder's Map, and we have no evidence to say he did more or less than them in it's creation. He isn't an Animagus but he can't be, his curse prevents it. Othen than those two things, what achievements can be pointed out that put Sirius and James above him?

Likewise we don't really see any evidence to suggest that Lavender is a "bad witch" All we really know about her is that she's a giggly gossip who likes fashion. Does this preclude the possiblity that she's a good witch? No.


My basic point seems is this. We don't really see enough of most wizards in canon to be able to assign them any meaningful place on a ranking of magical scale. This holds especially true for characters who only appear peripherally (James) Thus the fact that James and Sirius became Animagi can in no way be construed to mean that it's rare because only extremely talented wizards can do it.

 

My primary motivation in Lupin's placement was Snape's Worst Memory, which revealed that Lupin had to study to achieve the same grades that Sirius and James did effortlessly.

 

They could simply have better memories, you know.

 

I don't think many of the wizards mentioned on Taure's list are ordered correctly, namely Minerva and Bellatrix. Minerva is shown to be a teacher, but we're never told of the requirements for being a professor. Bellatrix should be ranked above Kingsley, as she defeats him in a duel.

As for James and Sirius, I think the fact that Barty, when impersonating Moody, took the Marauder's Map from Harry instead of making his own, suggests its a rather impressive accomplishment. They were also just 16, or younger. Seems to me that the placement of James and Sirius below Lily and Snape is rather subjective; James defied Voldemort 3 times, and Sirius defeats both Lucius and Dolohov (with some help from Harry) at the DoM battle. Snape creates spells, true, but Sirius and James both succeed in the Animagus transformation at a young age, a technique known to be very difficult.

I'm comfortable with the rest of the list.

Edit:
Having better memory equates to being better at magic, all other things being equal. The lack of practice on Sirius's and James's parts is indicative of an ability to pick things up easier, compared to Lupin.

 

Well we aren't told if their marks were better then those of Remus or not regarding the OWL example.