Leonardo Dicaprio left Jonah Hill ''scared s***less'' when he pretended to be a crazed fan.

Jonah was standing outside a store in New York when the 41-year-old actor suddenly appeared in front of him, clicking away on his phone, prompting the 'Super Bad' star to visibly jump in surprise and Jonah admitted it left him terrified.

He told Entertainment Tonight: ''It was funny! I was totally taken off guard. I was scared s**tless.''

However, he quickly realised it was just Leonardo pranking him and the pair shared a huge hug as they laughed off the joke.

Meanwhile, that wasn't the only recent case of mistaken identity for Johah, who admitted he confused Drake with his nutritionist.

The 32-year-old actor wanted to get in shape after gaining weight for his role in 'War Dogs', so he visited a dietary expert, who asked him to email him his food intake for the day, leading to an unfortunate mix up.

He recalled: ''I was just like at home, and I was bored, I was like 'Oh, I didn't email this guy.' So, I wrote down like yogurt, like salad, chicken, whatever, and I sent it to him.

''I was looking later, like an hour later, through my sent messages. He didn't email back. He usually just says OK or something, and it must've been 'D-R.' because it was 'Doctor', and I'd sent it to Drake.

''So Drake - who I don't know well at all - just got an email from me saying 'Yoghurt, salad, chicken' and then just Jonah at the end of it.' ''

Jonah is so embarrassed by the confusion, he joked he will now have to avoid the rapper in the future.

He added: ''He never wrote back. Never spoke to the guy. Another guy I've gotta duck for the rest of my life.''