As their name implies, these dogs combine the qualities of a terrier and a toy, although the toy characteristics soon became dominant in the breeding program. Once used to kill rats in large numbers, these dogs are alert and never overly nervous.

These charming little dogs are fun-loving and well-suited to any home environment. Their terrier influence makes them an inquisitive and energetic breed, but they are also content to spend the day at home with their human family.