Seven pounds. According to the Global Brand Animal Husbandry Network, landlubbers can grow up to seven pounds. Landlubber is a kind of duck bred in the southern region. It has dark green feathers and a corona on its head. It is larger than ordinary ducks, has a clumsier body, and has dense meat. It eats a lot, twice as much as an average duck. Landlubbers generally need to be raised for 5 to 6 months.