To say that "Guardians of the Galaxy" director James Gunn was in a good mood on Monday night would be an embarrassing understatement.

We caught up with Gunn at the red-carpet premiere for the latest Marvel Studios movie, "Thor: The Dark World," and this is how he described the ongoing editing process and his work so far on the sci-fi-superhero hybrid: "Everything else I've ever been through -- failed relationships, failed films, failed friendships -- everything I've ever done means nothing because I've just been created by God to make 'Guardians of the Galaxy' for you folks."

In addition to explaining how good he feels about how the movie is turning out, Gunn also filled us in on a few of the topics we're dying to know more about, including casting Bradley Cooper as a raccoon and Vin Diesel's still-unconfirmed involvement in the movie. Here's what we learned.

Bradley Cooper As Rocket Raccoon

Back at San Diego Comic-Con in July, Gunn told MTV News that the gun-toting little mammal named Rocket was his favorite character and the emotional crux of the movie. So it should come as no big surprise that the director would want someone along the lines of Academy Award nominee Cooper to bring him to life. On the "Thor" carpet, Gunn revealed how demanding he's been of Cooper -- and how the actor has delivered.

"I'm a very controlling guy. [Rocket Raccoon] is a big one for me, and I have very specific ideas about what Rocket Raccoon is like," Gunn said. "[Cooper] lets me push him any which way to get where I want to go. He does not give up. He sits there in the studio all day long until his voice is sore and his eyes are bloodshot, and he's bleeding from his nose and ears. But he's turned in some good raccoon voices, so who cares?" (He's joking, of course ... we think.)

What's Up With Vin?

It's strange when an actor insists that he's part of a movie but the studio hasn't officially acknowledged the casting. That's what is going on with Vin Diesel and the role of Groot. (Or, if you're more conspiratorially inclined, Thanos.) Marvel has yet to announce that Diesel has been cast as the sentient tree and Gunn can't comment, but it's clear that the director and actor have been talking.

"Honestly, I talked to Vin on the phone yesterday," Gunn revealed. "It's looking pretty good; we'll see." The director also confirmed that for the roles of both Rocket and Groot, some physical movement from the voice actors, including facial expressions and hand movements, is being recorded as potential reference for the animators, perhaps helping to explain why Diesel uploaded a video of himself walking on stilts.

["THOR: THE DARK WORLD" SPOILERS AHEAD]

The Post-"Thor" Tease

That wonderfully weird peek into the world of the Collector (Benicio Del Toro) after the first set of credit for "Thor: The Dark World" comes courtesy of Gunn. The director shot the teaser in just a few hours. "I got the script that morning, and I did it in two hours at the end of a day of second unit shooting," he said. "That's how this little bit came together with Benicio."

The small glimpse at Del Toro's performance is sure to turn heads, as it's probably the strangest thing to appear in a Marvel movie yet, but that's what has Gunn so excited about the character. "[Del Toro] is out there, man. He's the best," the director said. "We just kept watching him on set, being like, 'Oh my God.' He was probably the character who was most different from what I imagined. Although, I did say he's like an outer-space Liberace. That's what it says in the script, which he's kind of doing. He really came in prepared and doing something utterly unique, and he's mesmerizing the whole time he's in the movie."[END OF SPOILERS]

And if all of this is just too exciting to wait until next summer for, you might be in luck. Gunn confirmed that "we don't have that long to wait" before getting another look at footage from "Guardians of the Galaxy."

"Guardians of the Galaxy" opens in theaters on August 1, 2014.