Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Gwaihir attacks, target attacking creature gains
flying (This creature can't be blocked except by creatures with flying or reach.) until end of turn.
At the beginning of each end step, if you gained 3 or more life this turn, create a 3/3 white Bird creature token with
flying (This creature can't be blocked except by creatures with flying or reach.) and "Whenever this creature attacks, target attacking creature gains
flying (This creature can't be blocked except by creatures with flying or reach.) until end of turn."