It must rank as one of the strangest on-screen appearances of a horse's head since The Godfather.

Racing fan Graeme Hatt left millions of television viewers in stitches with his horsing around at a racing festival.

The prankster pulled a fast one on racing pundit John McCririck with the help of a novelty horse mask.

McCririck was reduced to a stunned silence when the pretend nag began nibbling on his ear.

Graeme, 31, of Boltro Road, Haywards Heath, pounced on the Channel 4 pundit at the Cheltenham Festival.

He said: "I was walking down to the course with my mates when I came across this joke shop.

"I was going to get an Ali G mask then I spotted the horse's head. It was just perfect and went down well with the crowds.

"When I saw John doing his bit I thought I'd get on the telly."

Graeme, who works for an oil company, sidled up to McCririck and, putting the mask on, pretended to nibble his ear.

He said: "He didn't notice me standing in camera shot at first until the giggles started and then he turned round and spotted me. I think he's a bit grumpy at the best of times.

"He said: 'Very funny, you've had your fun'. But by then everyone was in tears."

While the expert was not amused, millions of television viewers laughed themselves hoarse.

Graeme, this season's top scorer for Haywards Heath Football Club, said: "It was just a bit of fun on the spur of the moment."

A Channel 4 spokesman said: "People sometimes do things like this to John McCririck but he's a true professional."