Since there is no officially recognized teacup Chihuahua, or micro, pocket-sized, toy, or miniature Chihuahua breed or size, the word "teacup" can mean just about anything. A full-grown teacup Chihuahua could be on the small end of the 2- to 6-pound scale, he could be a normal-sized Chihuahua puppy, or he could be smaller than a normal Chihuahua.