Crocodile Hunter's son Robert Irwin stuns fans with stripped-down underwear ads

The 21-year-old son of the late Steve Irwin was revealed as the brand icon of an Australian underwear company Thursday. 

Robert posed for the ads in Bonds underwear but drew some inspiration from his zookeeper job. In a few of the shots, Robert could be seen holding reptiles.

"What in the Irwin is going on here," another added.

One user admitted, "Not the collab I was expecting - he looks SO good."

"Is this still April Fools," another joked.

Now Robert is all grown up and choosing to do "random exciting things," like the Bonds underwear campaign.

"I wish I could say I was very suave and cool about the whole thing, but I was like, 'Yes! Let's do it!' Because Bonds in Australia is an absolute icon," Robert added. "Also, I'm at this point in my life where I'm trying to do as many different and random exciting things, and if it's something that makes me a little bit nervous, that I've never done before and it's a bit of an adrenaline rush? That's what I want to be doing."

Robert followed in his father's footsteps - taking a job at the Australia Zoo. The zookeeper saw the Bonds ad as an opportunity to share his conservation message with a larger audience.

"We are all trying to continue an important legacy that my dad started," he explained. "I've gotten to find my own individual ways of doing that, and sometimes that comes in the form of modeling Bonds! It seems so out of the ordinary for what I would do, but I get to be with Aussie Wildlife, I get to approach a new audience, a new platform, and get my wildlife conservation message out there to more people. And that is what means so much to me and my family."

Robert celebrated his 21st birthday in November and took the moment to remember his father.

"Today I turn 21. I was looking through the archives a few days ago and I found these pictures of my dad on his 21st," he wrote on Instagram.

"It can be hard to celebrate the milestones when there's someone missing, but I will carry his memory and passion with me in this new chapter of life. I am one lucky guy to be surrounded by my amazing family today. Time to celebrate!"