magarena/release/Magarena/scripts/Verdant_Force.groovy

[
    new MagicAtUpkeepTrigger() {
        @Override
        public MagicEvent executeTrigger(final MagicGame game,final MagicPermanent permanent,final MagicPlayer upkeepPlayer) {
            return new MagicEvent(
                permanent,
                this,
                "PN puts a 1/1 green Saproling creature token onto the battlefield."
            );
        }
        @Override
        public void executeEvent(final MagicGame game, final MagicEvent event) {
            game.doAction(new MagicPlayTokenAction(event.getPlayer(),TokenCardDefinitions.get("Saproling")));
        }
    }
]