Which family's motto is "Hear me roar!" in 'Game of Thrones'?

Which HBO series is based on George R.R. Martin's 'A Song of Ice and Fire' novels? What is the name of the continent where most of 'Game of Thrones' takes place? What is the name of the throne in 'Game of Thrones'? Which family's motto is "Winter is coming" in 'Game of Thrones'? Who played Daenerys Targaryen in 'Game of Thrones'? Who played Jon Snow in 'Game of Thrones'? Who played Tyrion Lannister in 'Game of Thrones'? What is the name of the giant wall in the north in 'Game of Thrones'?