Racing pundit John McCririck is teaching the housemates the fine art of ‘tic-tac’ as he becomes the latest celebrity to take the reigns on Big Brother: Celebrity Hijack.

Introducing himself as ‘the fat, arm-waving, loud-mouth from Channel 4 racing’, the former Celebrity Big Brother housemate declared that the talented bunch would be treated to an afternoon of fun.

To whet their appetites, McCririck said: “You’re going to have a terrific time today and I will be teaching you something that may not be of any use in the outer world – but you’ll have a bit of fun doing it.”

McCririck, who has given himself the nickname Big McBrother John, revealed soon after that they would all be learning ‘tic-tac’ – the convoluted series of hand signals used by bookmakers at the races to express the betting price of the horses.

He has been calling housemates to the Diary Room one at a time to give them his expert advice.

But, as he’s a hijacker, there’s bound to be more to this task than meets the eye…

VIDEO: Watch John McCririck hijack the Big Brother house