magarena/release/Magarena/scripts/Roc_Egg.groovy

[
    new MagicWhenDiesTrigger() {
        @Override
        public MagicEvent getEvent(final MagicPermanent permanent) {
            return new MagicEvent(
                permanent,
                this,
                "PN puts a 3/3 white Bird creature token with flying onto the battlefield."
            );
        }

        @Override
        public void executeEvent(final MagicGame game, final MagicEvent event) {
            game.doAction(new MagicPlayTokenAction(event.getPlayer(),TokenCardDefinitions.get("Bird")));
        }
    }
]