Robert Irwin feared for his life when a 317kg crocodile named Jimmy Fallon locked him into a 'death roll'

Robert Irwin was left fearing for his life when a 317kg crocodile named Jimmy Fallon locked him into a “death roll”.

The 22-year-old conservationist - who is the son of late Crocodile Hunter Steve Irwin and his wife Terri - was taught by his dad how to handle the reptiles, but things almost went badly wrong during one particular encounter.

Speaking on The Tonight Show Starring Jimmy Fallon, he said: “I named this crocodile Jimmy Fallon, like, years ago, and he’s now what we call a boss croc. He’s huge, right?"

The talk show host was keen to defend his namesake and insisted the crocodile was actually "normal size".

He added: "It's just as you get older, you start to put some pounds on. I know what it’s like.”

Robert then laughed as he told the story of how he was almost crushed by the 14ft long creature.

He said: “We research crocodiles in the wild to better conserve them, right? The way you do that — my dad came up with this — is you actually have to jump on them, right?

“So I jumped on the back of Jimmy Fallon… and, get this, he death-rolled me. So I’m stuck underneath him with my arm hanging out. I’ve got like, probably, I don’t know, maybe 700 pounds on top of me? And I’m just like, ‘What do I do?’ "

Luckily, Jimmy Fallon the crocodile eventually “rolled back the other way” and Robert made it to safety.

He concluded: “I was fine, but he’s a goer, Jimmy. He’s a goer.”