Popster, Boros Steed

Flying, Vigilance
Create {x} 1/1 human tokens
were {x} is how much many you spent.
Whenever Pospster, Boros Steed attacks create {x} 1/1 Griffins with flying were
{x} is Popster, Boros Steed power and all 1/1 creatures gain flying until end of turn.