(the references are in the British book)
In bk 2, when they are wondering what riddle did to get a special awards, Ron says, maybe he murdered Myrtle, he would have done us all a favour! And guess what...that's what he'd done! (pg172)

In Bk 5, when Harry asks Lupin (or sirius, I can't remember) why YKW wants more followers, the reply is Voldermort is certainly not going to take on the Ministry of Magic with a dozen death eaters...need I remind you what happened? (pg88)

In Bk5, when Hermione wants to free Kreacher, Sirius says, Suggest to him that he leaves the house...and what happens? (pg103)
***
I think JKR is trying to screw up our minds with these stupid off the cuff hints that we think are jokes!
THis last one leads me off to think, perhaps Hermione isn't complete muggle, but part of the Blacks, and when she tried what Sirius suggested, Kreacher could leave.

Hagrid is evil. You want proof? Where was Pettigrew found when he left ron, why was he late delivering Harry, why was he the one who told harry how to get past fluffy when ykw was there, why is there a giant near the school when there is a giant-ykw alias (you believe they are brothers?)
And of course, it would make a good fight!
BTW, Neville will kick ass with an un-hexed wand - his father's wand was cursed. Watch the duel between him and Hermione!

In bk 1, why is he late delivering harry? And why did he describe the house as a burning weck, when it should have been fine? He didn't go there, that's why!
Then, at the exact time when YouKnowWho was in the Chamber, wanting nothing more than to meet Harry Potter, what happens? Hagrid tells Harry exactly how to get in. Coincidence?
Let's get started on Bk2. Hagrid was at school with YKW. Not condemning, but suggestive. And when Harry asked about Tom Riddle, there was no answer, although it would have been useful for Hagrid to have told us. We only have Tom's word, in fact, that Hagrid was expelled because of the Chamber of Secrets.
Ah, the fateful Bk3. The one where Pettigrew is found inside Hagrid's teapot. Not somewhere in the Kitchen, or in any of the multiple corridors of Hogwarts, but in Hagrid's Hut, one of the most difficult places to get to, no doubt. If Hagrid had wanted to, Fang would have found Pettigrew, but no, he is left undetected until Hermione fortuitously finds him.
In bk4, we discover little of Hagrid, but he is the one who is sorting out the maze, and he could have helped Harry.
In Bk 5, we find out that whoever leaked info to ykw was in the Hog's Head. Our only regular visitor we know of, although I concede he would be difficult to be concealed, is our mystery guest Hagrid! THe one who has giants surrounding Hogwarts! The same one who can see Thestrals and who has a weak will and would be easy to manipulate and uses an illegal pink umbrella-wand and loses his temper easily and would be able to get inside info on Hogwarts!

• Pettigrew was found in his teapot
• In bk4 when Harry needed to know the 1st challenge, and it was ykw's plan to get him through, he told hp about the dragon
• In bk1 he told hp how to get to the philosopher's stone so that he could meet ykw
• No-one suspects him (jkr trend)
• He has giants round the castle (how convenient)
• He could have swapped the children when he was late delivering hp (bk1)
• He was banned from the Hog's Head 15 years ago approx. This fits with the discription of whoever told ykw part of the prophecy
• We only have tom riddle's (possibly made up) diary to tell us that Hagrid was expelled for the chamber of secrets (I have to check whether DD confirmed this)
• He knew ykw at school and they could have known each other well
• (He has never been to the ootp headquarters, so he hasn't told anyone yet.)
• He can see thestrels (ok, so that is circumstantial evidence, but still a point)
• Only Harry, Neville and ykw have ever done magic without a wand, but Hagrid still knew in bk 1.
  (Gwir)

In bk4 when Harry needed to know the 1st challenge, and it was ykw's plan to get him through, he told hp about the dragon Are Hermione and Ron suspect, they helped Harry too. What about Dobby? He'd have never made it without the gillyweed.

In bk1 he told hp how to get to the philosopher's stone so that he could meet ykw Only when Harry tricked him into. He tried to get Harry to stop looking into stuff he wasn't supposed to. And I don't think it was LV's plan to meet Harry. He wanted to get the stone that time.

No-one suspects him (jkr trend) OH yeah, thats proof...hmmm no one suspects McGonagall either. Or I know its Molly Weasley! She's a death eater if ever I saw one! Or what about Hermione, the saucy wench!

He has giants round the castle (how convenient) Giants as in more than one? Evidence please. DD sent him to go get those giants anyway. He didn't go on his own.

He could have swapped the children when he was late delivering hp (bk1) Swapped who for Harry? How many kids do you think there are that look just like James with Lilly's eyes with a lightning bolt scar? That conveniently have a subconcious link with LV? And evidence again? You said you were offering proofs.

He was banned from the Hog's Head 15 years ago approx. This fits with the discription of whoever told ykw part of the prophecy. Point me? He was banned? He got Norbert in the Hogs head. But if you're right I'll grant you this one suspicious element.

We only have tom riddle's (possibly made up) diary to tell us that Hagrid was expelled for the chamber of secrets (I have to check whether DD confirmed this) Harry was inside riddle's memory. I guess it could be an elaborate forgery. But we have no evidence of anyone in Harry Potter's world being able to do something like that.

He knew ykw at school and they could have known each other well I'll bet something like 800 people were at school with Riddle one year or another. Do you suspect all of them. But if anyone knew LV well at school it was DD.

(He has never been to the ootp headquarters, so he hasn't told anyone yet.) He was away for at least 5 months of when the Order was formed, on business for the Order, I'll remind you. And all forms of leaving Hogwarts are being watched during the school year. How would he go?

He can see thestrels (ok, so that is circumstantial evidence, but still a point) Fail to see your point. Seeing someone die doesn't make you a Deatheater. His Dad died. He was in the Order the first time when people were dropping off like flies. If this is evidence of being a DE than Harry, Luna and Neville all should be under suspicion too.

Only Harry, Neville and ykw have ever done magic without a wand, but Hagrid still knew in bk 1. Very clear that Hagrid's wand is in his umbrella. Secondly, I doubt you're right. Seems like it is fairly typical of young witches and wizards to use magic instinctively. Collin Creevy mentions it too.

But all that aside, I don't agree with you, But who cares! Its a fun theory and you just go have fun with it! You've definately put a lot of thought into it! Who knows, maybe you're right and I'm wrong... (Flitwick)