The stunt was a jab at Trump’s promise to build a wall along the US border with Mexico if he wins the US presidential election – a contest for which, of course, he is one of the two leading candidates.
Trump is in Ayrshire, southwest Scotland, to re-open his Turnberry golf course after a lavish £200m refurb.
It is the first time Trump has visited the UK since a petition to ban him from the country was debated in Parliament. Following this morning’s referendum result, which led Prime Minister David Cameron to announce he would quit, Paddy Power is offering odds of 6/1 for a Donald Trump/Boris Johnson leadership double by the autumn.
In the US election, the bookmaker has priced a Trump victory at 5/2, lagging the Democratic candidate Hillary Clinton, who is odds-on favourite at 1/3.
A Paddy Power spokesperson said: "And David Cameron thought he was having a bad day. We gave Donald a good Guac-ing with this stunt, and it seems like voters will do the same in the polls. Still, at least he can blow his own Trump-et with our manhood market."
The bookmaker is also allowing punters to place bets on the size of Trump’s penis, after the subject came up in a Republican party debate. You can currently get 3/1 for 9.01 inches or more. "Now that’s a Trump Tower," said Paddy Power.