The Brat is not a purebred dog. It is a cross between the Boston Terrier and the Rat Terrier. The best way to determine the temperament of a mixed breed is to look up all breeds in the cross and know you can get any combination of any of the characteristics found in either breed. Not all of these designer hybrid dogs being bred are 50% purebred to 50% purebred. It is very common for breeders to breed multi-generation crosses.
"These are my Brat babies: The black and white is Jasmine at 4 years old. The brindle and white is Tinkerbell at 3 years old. They are not from the same litter, but they are both Brat Terriers. Jasmine's temperament is more like a Boston Terrier. She likes to stay home and play with people. Tinkerbell's temperament is more like a Rat Terrier. She likes to hunt outside in the back yard. We have a large pond and Tinker loves to chase the fish, birds, lizards, butterflies etc. She fell into the pond a few times and swam. They both are very intelligent. Jasmine can open the pantry door and can bring her bowl when she is hungry. She can close doors, growl, bark, roll over, beg, kiss, hug etc. etc. Tinker can do pretty much the same. They both understand English very well. They can even spell, like - G..O.. W..A..L..K.. P..A..R..K. They know when people are coming to visit us. I think they understand the word "coming", and know our friends and our friends' dog names."
ACHC, DDKC, DRA, IDCR