yes ..they can be mean & dangerous if not properly trained, just like pitts & any agressive breed. my best friend had one years ago & i re-named it Hamburger. she asked why ...because, i told her, if he doesn't stop biting my ankles i'm going to stomp it into hamburger. that said, i love the little devils. some of the breed varieties are absolutely gorgeous with their long silky hair. the miniatures are amazingly cute. the vet office i take my critters too has a preponderance of various pitt breeds & chihuahua breeds. so i get to meet lots of them ..and being the dog lover i am, i interact with all of them. if you are attracted to these tiny little loves, be sure to enroll it in obedience classes asap. sooner the better. and you also need to remember that strong personality breeds like chihuahuas, pitts, wolfdogs etc need constant teaching reinforcement. dogs are children that never grow up ..remind, teach & do again ..everyday.