In Sept 2004, I walked into Petsmart, and one of the local rescue groups was there with some dogs. One dog in particular caught my attention, he was listed as a 3YO black lab mix, he was about 50lbs. and sort of tall. She had just pulled him from a kill shelter the night before in Western Illinois, where he'd been found wandering, no collar, no chip, and no one claimed or adopted him, so he was going to be put down. He was super friendly, but very gaunt, and his coat was dull. His teeth were coated with gunk.
I looked at him, he had been dew clawed, and he had enormous feet. Something told me that this dog wasn't quite as "advertised", and a call was made to the husband, who came and was quickly smitten with this dog.
A trip was made to the vet that same day, she agreed with me that he was probably about 10 months old, most likely all lab, and that he would grow into those enormous feet. A quick tooth brushing, his teeth cleaned right up. He is now a very tall, 85lb lap dog.
I also had a coworker who adopted what she thought, and had been told, was a young adult Beagle. Turned out he was a young Treeing Walker Coonhound. oops!