// Dormant Gomazoa doesn't untap during your untap step.
this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new SkipUntapSourceEffect()));
// Whenever you become the target of a spell, you may untap Dormant Gomazoa.
this.addAbility(new BecomesTargetControllerSpellTriggeredAbility(new UntapSourceEffect(), true));
}