Wait. Wait. You said Thursday would have a tough dog, right? That is not a big, mean, tough dog like a Rottweiler or pit bull. That is a giant Beanie Baby made real.
Actually, the Shar-pei is one of the most ancient dog breeds in existence. As the name might suggest, this breed originated in China, and has a black tongue like the Chow Chow. Shar-pei are known for their baggy skin (especially as puppies), courage, and rarity. This does not mean that there are no puppies waiting to be hugged.
Adorable though those wrinkly puppies may be, they still show the Shar-Pei's fighting lineage when playing. The loose, rough skin of the Shar-pei allows the dog to bite back if the skin is grabbed, giving it an advantage in the dog pits. Fighting Shar-pei was reserved for the upper classes in China; among peasants, the Shar-pei was used as a guard dog, cowherd, and boar hunter. That thick skin has multiple applications!
The Shar-pei's unique skin is a mutant form of the gene coding for hyaluronic acid, a substance found in the skin, connective tissues, and brain matter. A similar malfunction can occur in humans, also leading to excessive wrinkles. This sounds like the best job ever .
As one might imagine, overbreeding for wrinkles causes considerable problems. The "Western" Shar-pei is known to have its own disease, Familial Shar-Pei fever, due to overbreeding for adult wrinkles. They are also notoriously allergic to any grain-based dog foods, again probably due to that strange skin. It is important to find a good Shar-pei breeder if you wish to acquire one of these strange dogs, so research research research!