// When Briarhorn enters the battlefield, target creature gets +3/+3 until end of turn.
Ability ability = new EntersBattlefieldTriggeredAbility(new BoostTargetEffect(3,3, Duration.EndOfTurn));
ability.addTarget(new TargetCreaturePermanent());
this.addAbility(ability);
// Evoke {1}{G}
this.addAbility(new EvokeAbility(this, "{1}{G}"));
}