Huff Puff the hedgehog is thought to be Britain's biggest at an average of three and a half times the size of her spiky contemporaries.
The nine-month-old female weighs in at 2.04kg - the weight of a small cat - and is the size of a football.
She piled on the pounds after gorging on cat treats and dog food at the Furze Pig Hedgehog Rescue Center in Ross on Wye, Herefordshire, where she was taken as an orphan. The 15 other hedgehogs at the center weigh around 600g each, so staff have decided to put Huff-Puff on a calorie-controlled diet.
Maureen Webb, 60, who runs the center named her new arrival because of her "stroppy" nature. "She's a real little madam and a right prima donna. When you approach her she huffs and puffs - hence the name," she said. "The problem is I can't release her until she's the right size because she won't survive."