Giant bunnies are rabbits that typically weigh 12 pounds or heavier as adults. The most common giant rabbit breeds include Flemish giants, checkered giants, British giants and giant chinchillas.
The Flemish giant is the largest of all the giant rabbit breeds, weighing at least 13 to 14 pounds at minimum with weights of 22 pounds or more commonly reported. Does reach their adult weight by the age of one year, while bucks take a year and a half to reach maturity. The American Rabbit Breeders Association recommends waiting to breed until the rabbit hits adult weight, at which point they can continue to breed until age five to eight years.