Don't let the Xoloitzcuintli's appearance put you off, for underneath that unusual exterior is a loving canine companion. Also known as the Mexican Hairless, this 3,000-year-old breed comes in three sizes (toy, miniature, and standard) and two varieties (hairless and coated). Regardless of size and hair (or lack thereof), the Xolo is an excellent watchdog who enjoys snuggling with their favorite person.