The Chihuahua is a small breed of dog known for its compact size and big personality. They typically weigh between 2 and 6 pounds (0.9-2.7 kilograms) and have a variety of coat types, including short-haired and long-haired varieties. 

Chihuahuas are known for their apple-shaped head and large, expressive eyes. They have a strong personality and can be both loyal and protective of their owners. 

Chihuahuas can adapt well to various living environments, including apartments, but they should be protected from extreme temperatures due to their small size. They have a moderate energy level and require daily exercise through walks and playtime. Chihuahuas can be bold, confident, and fearless, sometimes displaying a “big dog” attitude. Proper training and socialization are essential to help them become well-behaved companions.