Knowledge(Nature) to identify a Wolf is a DC 11 check. So, you need 1 rank in Knowledge(Nature) since it must be trained; without that, you just think it's a big nasty dog. But we'll say you have 1 point in Know(Nature); what Int would it take to have a chance to not be able to recognize a wolf in calm circumstances? 8-9. That gives you a -1 Int mod netting +0 on the check so Take 10 wouldn't guarantee ID. Even then, you've got a 45% chance of correctly identifying the big snarling canine as a Wolf rather than just a big snarling animal. What would an Int of 7 get you? A 40% chance of success. You're only marginally less likely to realize what kind of animal it is. With an Int score of 3, a -4 modifier, you have a 35% chance. Even with an Int of 3, barely above that of the Wolf itself, you have over a 1/3 chance to correctly identify it as a Wolf while a person with 10-11 Int, the de facto average Int for a person only has a 1/2 chance and, with just 10 Int, you can always ID the Wolf in casual circumstances by taking 10. And this is with a mere 1 point in Knowledge(Nature) and it not being a class skill.
A couple things you may want to take into account, first of all common monsters (the example given is goblin, which I'd argue is less common than wolves) are a DC 5+CR so the wolf's knowledge DC is 6. That easily falls into the range for untrained knowledge checks. Second, a successful skill check gives you significantly more than just identification, it also gives powers and vulnerabilities. Mechanically that means that in a take 10 situation an untrained human with a 2 Int will still make the check, so by the letter of the rules you can't be "I wanna pet the big puppy" dumb without adverse conditions.
That being said, the monster id system has some fairly major issues (like it's technically harder to tell what a really big red dragon(DC32) is than it is to identify a baby(DC 16)) so I'd take that with a pretty big grain of salt.