1862, September 20 (pre): Mrs. Scott and the Coal Toad
Sometime previous to September 20, 1862, when an account of this matter was published, Mr. John Scott of the Great Western Railway in Paddington, stated that his wife had seen, many years previously, her father's workmen split open a piece of coal that contained a moderate sized frog or toad in the middle of it. It was alive and able to move, and the hole it had occupied had an oval shape and a smooth internal surface where the animal had lain for an unknown amount of time.
I currently have only one source for this tale, and even that is referencing to a letter written by someone else who claims that they knew Samuel Goodwin for twenty-five years, and that he was trustworthy. Still, that makes this a tale about a friend of a friend... and so it will remain labeled a 'legend' until I can dig up more information, starting with the original article.