ill tempered, too hyper, or untrustworthy of people, or crazy. I have only met about two or three who were nice. As a groomer I meet a lot of the same breed.
And chihuahua? Ugh. May be 'easy' to care for but those things are little turds! Not to mention ugly with those big ol' apple heads and buggy eyes. And not to mention annoying and nippy, and they shake ALL the time.