The Guinness Book of Records recognizes a Mastiff by the name of Zorba as the world's biggest dog, weighing in at a hefty 343lbs.
About the Mastiff
Character-wise, Mastiffs are a rare combination of nobility and courage. These calm dogs are affectionate with their human companions, and despite their size are known to be gentle with children.
Mastiffs are powerful, well-built dogs who have even been known to outweigh fully grown men. They are used across the world as security and watchdogs thanks to their alert, protective nature and formidable appearance.
Source: key facts and characteristics sourced from Fédération Cynologique Internationale (FCI)