The Mystery Cartoon Character Game, ongoing-ier.

Ooh, I know this one, and it's from an untapped source; bravo for that. But I'm going to keep quiet and give someone else a chance.

I guess three more clues are needed:

4. I have encounters with many others, including a pair of moose.

5. Although I do become human again, I decide to stay in my new form after a while.

6. In the sequel, I marry my lady when she becomes just like me.

Looks like I'll have to post the last three clues after all:

7. Both of my movies have alliterative titles.

8. My name begins with the same letter as that of my buddy.,

9. The moose I mentioned in an earlier clue are modeled after a Canadian comedy duo, and voiced by them as well.

This is Kenai, from Brother Bear (and Brother Bear 2).

Welcome back, Pete. You got it. So the board is yours once again . Good job. . Now to explain the clues:

1. Convinced that bears are thieves, he kills one.

2. He then becomes a bear himself.

3. The bear he killed was Koda's mom.

4. Self-explanatory.

5. Although he regains his true human form, he decides he'd rather go on being a bear.

6. He marries Nita when she becomes a she-bear.

7 and 8 are self-explanatory.

9. The two moose are modeled after Bob and Doug MacKenzie, and voiced by their portrayers Dave Thomas and Rick Moranis.

Thank you Emeraldisle, and thank you OUB for allowing me the opportunity to answer! (but where is everyone else?)
Now here's a popular character we haven't had yet...

1) Originally, it would seem, from Brooklyn, I've attached myself to a travelling organisation, for peanuts.

2) I replace a bird called "Red" in the original story.

3) The plot of the movie takes off when my protogé and I get crocked.

Sorry, Pete. Don't know this one at all.

Could this be Timothy Q. Mouse from Disney's Dumbo? I'm thinking "crocked," refers to he and Dumbo becoming intoxicated, leading to that surreal pink-elephants-on-parade sequence.

It not only could be - it is!

1) Speaks with a Brooklynese accent, courtesy of actor Edward Brophy; he is travelling with the circus, eating the discarded peanuts.

2) In the first story draft, and the Disney-published book based on the story by Helen Aberson and Harold Pearl, Dumbo's mentor was a robin called "Red". At one point the story development took a psychological turn, focusing on a Freudian Owl analysing Dumbo's subconscious fears, which of course brought up the elephant's supposed fear of mice. The psychology angle was dropped, but the idea of a mouse being able to scare the elephants remained, and Timothy took on Red's role.

3) Yes indeed, the plot certainly "took off" when Timothy and Dumbo got drunk on champagne, and woke up at the top of a tree!

Well spotted, OUB - award yourself a lovely big point, and bring on your next character!

Oh my, that felt good. Bravo for picking a character from a Disney feature film, too. Therefore, I must raise my bar.

1) This character occurs routinely in a regularly televised animated series produced by Walt Disney Television.

2) This character is a Good Guy, working alongside others of like mind to set right that which has gone wrong.

3) Curiously, while all the other human and non-human characters can speak English, this character doesn't, though he comprehends English perfectly, and can make himself understood to his teammates.

I do know this, but since Glowworm's here, I'll let her figure it out.

I assume this may be Zipper--the fly from Rescue Rangers.

That assumption is absolutely correct. This is Zipper the housefly from Disney's Rescue Rangers series. Chip, Dale, Monterrey Jack and Gadget all speak English, while Zipper speaks ... like a mouse with a sore throat reciting Yosemite Sam dialog backwards. Good deduction, Glowworm; it nets you a fresh +1, plus control of the board.

Thanks, I've seen a few episodes to know that the little guy doesn't really speak our language.
Here we go.
1. I am the pet of a famous legendary character.
2. This short is known for being the only one in 3D.
3. In the end I go after a giant tree.

I know the answer, but can't provide it, for that would be cheating in a way.

Ah, yes. It's Smidgen, from Lumberjack Rabbit.

Yeah, got inspired by the A to Z character game. Smidgen is Paul Bunyan's giant dog. This is the only 3D Bugs Bunny short, and it ends with Smidgen heading off to turn a giant redwood into a giant doggy toilet.

Got one....

I was raised in an abbey after I lost my family.
I have the spirit of a warrior.
This TV series is based on a series of novels.

I haven't a single clue. Maybe someone else has seen it.

? Hmm, this has me blanked as well. The only character I can think of raised in an abbey would be the Countess de Winter from Alexandre Dumas' The Three Musketeers. She, however, has never been animated, as far as I know, and has more the spirit of a spy than a warrior. The only other inkling I glean from the clues is "abbey" which is a term from the United Kingdom; in most other places, it'd be called a monastery.