Transcript for 'America's Sexiest Vet' on promoting conservation with his show 'Evan Goes Wild'
Reporter: Tall, dark and handsome meet adorable and fluffy. This is Dr. Evan antin. Every time I walk by him he'll talk to me or whistle at me or something. What's he say? Hey, doc. He'll say hello or he'll whistle at me. Sometimes he does the cat call. Reporter: Instagram star now with more than 1.2 million followers and a loyal YouTube following. But first and foremost he's a veterinarian. He's really great. He's easygoing. Of course he's easy on the eyes. But I have a husband. So don't put that on camera. Reporter: Treating everything from exotic birds to cuddly rabbit patients at his office in southern California. No one would go back if he wasn't a good vet. The looks can only get you so far. Very true. Reporter: "Nightline" first met him in 2016. Getting to the gym is something I like to do on a daily basis. Reporter: Fans saw his hunky good looks and jawline on social media earning him a reputation as America's sexiest vet. Are you sick of people talking about your hotness? I mean, it's not a bad thing. So it's not like I'm offend bid it or whatever. Fine, if my jawline saves the elephant, I'll take one for the team. Oh, my god. I try to stay in shape and healthy and whatever. But like I just love what I do. And seriously, if it helps me get to do what I love to do then so be it. You are known as America's hottest vet, but what do you want people to know you as? Spreading awareness for wildlife conservation and showing what vet medicine is all about and trying to educate people about animals in general. I'm talking to elephants. Reporter: Today the 34-year-old's traveling the globe for his animal planet show "Evan goes wild." Mouth looks good. Give me a big mouth. Yes, that looks very good. Reporter: Sharing his medical kills in underserved communities and remote areas around the world with little to know veterinary health care. It's all in the name of animal conservation. They're right next to me. This is crazy! Oh, my god, it's a dream come true. I think I have fur in my mouth. I'm sorry. Pause the interview. Yeah, it's my dream show. It's me getting to work with wildlife around the world and spread wildlife conservation and awareness. And I'm a vet. So I get to work on individual animals and share their stories. What did you have to do to go from, you know, little Evan to big-time TV star doctor? I put everything together. I love the sciences. I love medicine and surgery. Obviously animals are a huge part of my life and something I'm passionate about. I think this is my calling. I worked toward becoming a vet aggressively. I know this is my calling. I know this is where I belong on this Earth to be doing. There's a big lizard sitting right there. I think there's something wrong with his mouth. I need to be clear. I have a lot of experience working with monitors and I don't want anybody trying this at home. Reporter: Not afraid of violent creatures, Dr. Antin leaves it all on the line. There are some places I saw where it seemed like your cameraman couldn't even keep up with you. Do you ever get nervous? I work with a lot of dangerous animals and I have a healthy respect for those animals. And there are moments that when I work with wildlife and even on the show where like we have some close calls. It's a reality check. All right. Whoo. Whoo. Hey, beautiful. Getting up close and personal with everything from whales -- I'm chasing my dream right now. Reporter: To bearcats. Just going to hang on by their tails. Reporter: To elephants. I'm putting in some of her favorite grains and some fruits and a little bit of molasses to sweeten it up. And then the medications. Reporter: The scarier thing he says are the realities he's witnessed for animals around the planet. It seems like sometimes it's fight for conservation against poaching and littering and pollution and climate change and everything seems futile. When you see these people that are so passionate about it and they devote their lives, their income, their time,ar their everything into helping wildlife and domestics around the world, I think that sparks passion in Reporter: He hopes to encourage viewers to take conservation into their own hands. Try to avoid straws. Really single-serving plastics in general. Reporter: Have you seen that in your travels? The wildlife you're trying to help being affected by plastics. It's heartbreaking. You go to an urban area or city and you see their waterway. It looks like a dump. Reporter: Dr. Evan says he takes his growing fame in stride. It's all for the love of animals. Do you get recognized walking On occasion, yeah. Reporter: What do people say? They just say they think I'm Henry Cavill or -- Which is fine. That's good. Yeah, no, he's a stud. He's cool. Or that you know, they just say I love what you do with animals or I love your Instagram page or your show or whatever. Reporter: True fans already know that Dr. Antin is off the market. This is so adorable. Whole gang's all here. Reporter: We had a chance to meet the whole family. Including the woman whose been supporting his dream from the very beginning. His fiance Natalie. When I was a punk snowboarder undergrad, she believed in me then. Yeah. He had long hair and everything. No. Really? Reporter: The two met 13 years ago. We met on a cruise ship, and he very specifically said he was so inspired by people like Steve Irwin and Jeff Corwin, and we talked -- we had a mutual love for both of them. So we talked about that. He even said he wanted to be on animal planet. Reporter: And now that her fiance's been dubbed by "People" magazine as the sexiest beast charmer in America, what does she think? It was honestly hilarious. I think I laughed more than anything. Reporter: So maybe she thinks the title's a bit, well, ridiculous. But anything to help save the planet she's all in. I'm like proud that he has built this platform and that he uses it for such a good purpose. And people listen to him. And I think it's a really amazing, wonderful part of this like world of technology that we live in. See you guys next time. Reporter: For "Nightline" I'm Maggie Rulli in calabasas, California. You can watch "Evan goes wild" on animal planet go.
This transcript has been automatically generated and may not be 100% accurate.