Presa Canarios are a mix of different Molosser breeds, typically Canary Islands Mastiffs, Spanish Mastiffs, and English Mastiffs. This large, muscular dog was originally bred for working livestock on the island of Gran Canaria. The Presa Canario is known for its strength, size, and aggressive temperament. Although they can make loyal and loving family pets, they are not recommended for first-time dog owners or families with small children.