According to the Black Russian Terrier Club of America, behavioral problems occur when a BRT is left to its own devices, relegated to the backyard with little human contact.

At 13-weeks-old Russian Terrier, Mig, is a cute, black, fluffy ball of energy. When fully grown, he’ll be bigger than a German Shepherd and strong enough to push a man down to the ground.

According to the American Kennel Club, the Miniature Bull Terrier usually is about 10-14 inches (25.4 to 35.5 cm) tall, and weighs between 18-28 pounds (8.2-12.7 kilograms).