Goliath of Castle Shores

As long as you control less than 5 forests, Goliath
of Castle Shores is a creature. If you control 5 or
more forests, Goliath of Castle shores becomes a Legendary Land called Castle Shores with "Add {g}{u}" and "{g}{u}{3} Sacrifice this land, you may
put as many lands onto he battlefield from your
hand until end of turn."
"He has been the protector of our lands for many centuries, may he never be brought to harm. As payment for his service, what do we gift him in return?"