
Sorry guest there are no such breeds. Please go to the Kennel Club website click on breed standards and find the two breeds Maltrese and both kinds of Chihuahua (long and Smooth coated) and read what the requirements are for size.
Teacup is a phrase coined mostly by US puppy farmers to describe weak unhealthy pups in an apealing way. These breeds are Toy breeds but should never be weedy or too small.