Burger chain McDonald's, which this week threatened to sue a tiny corner shop named McMunchies, is facing legal retaliation - from an Aberdeen man called Ronald McDonald.
He claims the fast food chain has pinched his name and pinned it it on the colourful clown which entertains its young customers.
And he says that he may sue McDoanld's if it goes ahead with its plans to force a sandwich shop in England to stop using the name McMunchies.
The American corporation claims that the shop in Buckinghamshire could mislead customers by using the Mc prefix.
But Mr McDonald, a 61 year-old retired history teacher from Westhill, says the threat is an insult from a company which has belittled generations of Scots.
"Frankly, I always feel a bit annoyed that my name is the same as a clown, especially when I read of this action by the company," he said.
"As far as I'm concerned they ahve stolen my name and my father's name for commercial purposes.
"To me it's an attack on the Scottish clan system. They have no right to claim the prefix Mc or Mac as theirs."
Mr McDonald, known to his friends as Big Mac, wrote to the company's managing director enclosing a Doric poem and telling him:
"The prefix Mc and the name McDonald has been used in Scotland and spread worldwide many centuries before your firm was ever in existence.
Mr McDonald, who was principal history teahcer at Torry Academy when he retired, has yet to recieve a response. He said he would consider legal action if the company's reply were not satisfactory, even though individuals' names are not their copyright.
But a McDonald's spokesman said: "He has completely misunderstood what we're doing about McMunchies
"It 's got nothing to do with the Mc prefix, other than in a food service context.
"We believe Ms Blair, the owner, is certainly seeking to confuse customers into thinking that there may be some association with McDonald's, particularly with our unique stylised writing, and we hope she will remove the Mc prefix from her shop.
"Of course the Mc isn't copyright when it's a family name, or a shoe shop or whatever."
He said the company would clarify its position to Mr McDonald.