The Staffordshire Terrier is known as an aggressive breed. It is related to the Pit Bull, and it must be very well trained as a puppy, otherwise its aggression will be uncontrollable. When well trained, they can be extremely friendly with humans. However, if not trained properly, they can become aggressive. It is therefore very risky to own a Staffordshire Terrier as a pet.
As you might be able to tell from the name, this dog breed is originally from the Canary Islands. This dog breed was originally bred for herding animals, but it has a very bad reputation for being aggressive. Presa Canarios are banned in many locales because they can be so dangerous. So if you have children, it is inadvisable to own a Presa Canario.