Fingernails don’t grow after you die.
Despite what you may have seen on other lists of random trivia, your fingernails and hair do not, in fact, continue to grow after you die. To grow, these must have a steady supply of glucose, which is cut off after the heart stops beating, preventing any further growth. In fact, the skin around the hair follicles and nails dehydrates after death and partly retracts, which can make them appear longer.