this.addAbility(new MorphAbility(this, new RevealTargetFromHandCost(new TargetCardInHand(filter))));
// When Horde Ambusher is turned face up, target creature can't block this turn.
Effect effect = new CantBlockTargetEffect(Duration.EndOfTurn);
effect.setText("target creature can't block this turn");
Ability ability = new TurnedFaceUpSourceTriggeredAbility(effect);
ability.addTarget(new TargetCreaturePermanent());
this.addAbility(ability);
}