this.power = new MageInt(2);
this.toughness = new MageInt(3);
// {tap}: Target Merfolk creature gets +1/+1 and gains islandwalk until end of turn.
Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new BoostTargetEffect(1,1, Duration.EndOfTurn), new TapSourceCost());
ability.addEffect(new GainAbilityTargetEffect(new IslandwalkAbility(), Duration.EndOfTurn));
Target target = new TargetCreaturePermanent(filter);
ability.addTarget(target);
this.addAbility(ability);
// {tap}: Target land becomes an Island until end of turn.