Every day, the cheeky black and white moggy walks the 50 yards across the cobbled street from the restaurant where she lives.
She then strolls past armed cops and guardsmen to the Queen’s apartments, where staff feed her along with the royal corgis.
Mime’s owner, restaurant boss Kevin Lam, 69, said: “She won’t eat any of our leftovers.
“She’s been going for about four years.
“A courtier told me the corgis used to fight with her at first, but after lots of barking and some hissing they came to a sort of truce.”
He added: “On the Queen’s birthday the Army locked the Henry VIII gates but the security guys opened one to let Mime through.
“After she’s fed she wanders back and goes to sleep in front of the fire.”
A castle source said: “Mime’s part of the furniture.
“Everyone looks forward to her visits.”