In the image, Robert is cradling a noticeably injured black swan as blood gushes out of his left knee. Fans were quick to notice the battle wound.
"That knee though!" one user penned in the comments.
"Your poor leg😮" another shocked fan added.
"Be careful next time! That knee cut must’ve hurt :(" a third wrote.
Others applauded the teenager's fearlessness, pointing out how the Wildlife Warrior took after his dad. One wrote, "This kid, just like his Father, NO FEAR!".
Another Irwin who bears a striking resemblance to their parent is Bindi Irwin and Chandler Powell's baby daughter, Grace Warrior.
The three-month-old bub has already been deemed a mini Bindi after Robert delighted fans with a close-up black-and-white portrait of the newborn.
The proud uncle wrote on Instagram, "Look at my lil niece!!!! 😊".
Soon after, the comments section was lit up with fans pointing out the bub's physical similarities to her mum Bindi.
WATCH: Chandler Powell cracks hilarious dad joke with Robert Irwin (Story continues after video)
The 22-year-old recently spoke candidly about her father Steve not being able to witness his first granddaughter growing up.
In another sneak peek for their upcoming show, an emotional Bindi vulnerably said, “It’s hard knowing that she’ll never actually meet him, and it’s devastating because I’ll never get to watch their connection."
“Its going to be really special for her to know him through us, to tell her about what an amazing man he was.”