Clark Gregg has had a fascinating relationship with his Marvel Cinematic Universe character Agent Phil Coulson. The character showed up in the very first MCU movie, "Iron Man," as sort of a throwaway cameo and a tip of the hat to the very big things the studio had in store. But little by little his cache grew, until in "The Avengers," he was responsible for the formation of the team (at the expense of his life, unfortunately). From then, things have gotten really unpredictable; the formerly dead agent has been the focal point for a primetime television series called "Agents of SHIELD" (it's run for more than 100 episodes) and, with this week's "Captain Marvel," we get to go back in time and see a young, fresh-faced Agent Coulson as he navigates the organization in the mid-1990s.

We got to sit down with Gregg and talk about his character's unexpected journey, including a really tantalizing idea for a "Riverdale"-style spin-off.

Moviefone: Let’s start at the beginning. You did the original “Iron Man” as a favor to director Jon Favreau, correct?

Gregg: No it wasn’t a favor. I was wary about it because in the script it was a guy named Agent and he had about six lines, which I still would have done, because I love “Iron Man” and that was an amazing cast. But I think I had just been cut out of something except for like one thing. It was an extraneous storyline.

What was it?

I can't remember that I knew I was traumatized by it because friends of mine were like, “Did I see you in this?” And I went, “Oh this is so humiliating.” When I'm 40. I am 40 and they're saying to me, “Was that you in that?”

And I was afraid with that cast that would happen again. So I had a very tiny moment of hesitation before my wife slapped me in the back of the head and said, “You love this stuff. Yeah, go do it. Maybe they won't cut you out.” And that thing happened that never happens that you always fantasize will happen where they go, “You know, we think we might add some more stuff for your character.”

And that was during production?

Yeah.

And then when did you know that you were coming back for other things?

Well, I thought it was weird. It was weird because again, even when it was like seven lines or something, they were like, “Would you want to make a three-picture deal?” And I was like, “Oh wow.” And they said, “Let's just what they're doing, they're doing it with everybody, you know, the background is making a three-picture deal.” So I said “okay” but I didn’t think they would actually use it. And then four or five months later they said, “Listen, there's a couple of scenes in ‘Iron Man 2,’” but I think one of them got cut out. It's on the DVD. It's me and Gwyneth during the hearings talking about chili and talking about how Tony Stark is blowing it.

I kept thinking, Well, that was fun, that was really cool, I love what they're doing. And then they keep going, “Well, actually I think you're going to be the one to find Thor's hammer.” So I got to geek out over and over again.

And then you’re the catalyst for the Avengers getting together.

Yes. It was a funny phone call. I had been at Comic Con. I mean funnily after watching the panels at Comic Con, they said, “Actually you're in the panel this time, in ‘Thor,’ you're in the panel.” It's like that's cool. And I was backstage, I can't believe I survived any of this. I was backstage waiting to do the panel and then a guy who I knew to be Joss Whedon comes up and goes, “Hey listen, the big surprise is we're going to introduce the cast of ‘The Avengers’ and I’m writing something really great for you. Will you come on stage with the cast of ‘The Avengers?’”

At that point I thought it was la Make-A-Wish thing, just nobody had told me I was dying. And then I went out there. A couple of months later they said, “Hey, Joss wasn't kidding. He really wrote you some great stuff in ‘The Avengers.’” So I was like, “Wow, this is amazing.” And they said, “Yeah, what happens to you is what brings the Avengers together.” And it was, that was the first moment I went, “Oh.”

So how did Joss tell you?

That was it. They sent me the script and I was like, “Wow, that's so glorious.” I don't think I'm dead, you know. But yeah, I mean, is this real? Do you guys want to shoot an alt version where I'm just wounded by Loki? They were like, “No, no, no.” Here’s what we can offer you. And they came over with an iPad and they showed me the early digital pre-viz of Hulk smashing Loki like a rag doll. I was like, “Well that makes me feel a little bit better.” But it was done. And then I don't think anyone was prepared for, certainly not me, for the Colson lives [movement]; the hashtag and the global outrage. And I guess it was enough people that they thought, Maybe there's a TV show here. I think Bob Iger said, “You know, I've seen some of these One Shots, why don't we do a show?” And next thing you know I get a call from Josh and Jeff Loeb saying, “We think you might not be so dead. And here's the interesting mythology that makes this a cool buy back.”

And “Agents of SHIELD” connects to “Captain Marvel” in the sense that you were resurrected with Kree technology, right?

Correct. Kree Technology and blood. There was a Kree body and there are those already who are suspecting it may be someone from this [“Captain Marvel”]. That was originally used as part of a, a super-secret program called the Tahiti project. And they had this in case they needed to resurrect the fallen Avenger. Why Nick Fury chose or ABC chose to use that on poor old Phil Coulson, because apparently it was a miserable experience and then to wipe all those memories because he was so traumatized, remains to be seen. But it became this metaphor for the cost of being brought back and post-traumatic stress. And it became this whole mystery all through the first season that was artful and brilliantly thought out by Joss.

Yeah, but now, you're dead again.

Go figure.

Do you still enjoy playing the character?

I do. It's really fun. If I didn't, it would suck and I would have found a way to stay dead. But so far I go, “Really? I'm n still not dead?” And then they’re like, “Well listen, here's our idea. What do you think?” And then tell me what, what the Whedons Jed and Mo now, what they have to say … I'm always kind of like, this is not going to be good. And then I hear it and I go, “Okay, that is too cool. I have to try to do that. That's insane.”

So what was your reaction when they said we're doing, a 90s-set buddy action movie?

I mean the idea of anything in the 90 sounds cool to me because I knew that I knew that Ryan and Anna would have a bad ass playlist involved and the idea of stripping away the jaded, battered SHIELD agent that Phil Coulson is in season five of “Agents of SHIELD” shield and going back to early days when he's just man-crushing on Nick Fury and trying to figure out what the hell SHIELD really is, that sounded fun to me.

Did the technical aspect of it seem daunting?

I didn't have to do it. They said, “we’ll get you a trainer” and they said “dude, there is no trainer who can get me back to the 90s.” And they said, “Well, not your face. And there was a really gruesome, I forgot about this … They said, “Can you stop by hair and makeup, they really want to meet you on Captain Marvel?” And I was like, “Okay.” So I go over, cause they’re at Sony and I'm shooting ‘SHIELD’ in Culver Studios about a mile away. And I go over and I walk in the trailer and it’s so funny, they're like doctors. All of a sudden I had all of them crowd, about three or four different people within six inches of my face going, “Look at that. Okay, but we're going to do about that.” Looking at my hair like, “Oh that's not good. What are we going to do about that?” I mean it's taken me months to recover from what's happening, right. This is horrible. And they said, “Oh sorry, never mind. We were saying that out loud? No, it's fine. You look great actually.” I said, “What do you want me to do, do you want me to move into a Botox clinic?” And they said, actually no, they need the wrinkles. Well good then I've got some stuff for them to use. And, uh, and then on the day it's just really black dots on me, white dots on Sam, and we're just imagining each other younger and fresher.

Where do you want to see Asian Colson go next?

I mean, I feel like I would be greedy to say anymore. I've already gotten so many periods of his life. You know, I would love the idea of a teenage, kind of “Riverdale” of SHIELD where some younger person got to put in the long hours, and I just came in to be like the voice in “How I Met Your Mother.” 

“Captain Marvel” is everywhere tonight.