What Will My Black Lab/chihuahua Mix Look Like?

Mixed breeds can take any traits or combination of traits from the breeds involved with even litter mates ending up completely differently from each other. They don't have set genetics that lead to predictability like a pure bred you are mixing the genetics from more than one breed and widening the possibilities. You would study up on both breeds to learn the possibilities and you can try looking around on petfinder for some same or similar mixes to get some ideas.It's unlikely a female Chihuahua would survive that.  
www.petfinder.com
www.chihuahuaclubofamerica.com www.thelabradorclub.com  
home.comcast.net  
www.learntobreed.com  
www.terrificpets.com  
www.wildheirlabradorrescue.org