diff --git a/Mage.Sets/src/mage/cards/s/SeafloorStalker.java b/Mage.Sets/src/mage/cards/s/SeafloorStalker.java
new file mode 100644
index 00000000000..e565b1224c4
--- /dev/null
+++ b/Mage.Sets/src/mage/cards/s/SeafloorStalker.java
@@ -0,0 +1,94 @@
+package mage.cards.s;
+
+import mage.MageInt;
+import mage.abilities.Ability;
+import mage.abilities.common.SimpleActivatedAbility;
+import mage.abilities.common.SimpleStaticAbility;
+import mage.abilities.costs.mana.ManaCostsImpl;
+import mage.abilities.dynamicvalue.common.PartyCount;
+import mage.abilities.effects.common.InfoEffect;
+import mage.abilities.effects.common.combat.CantBeBlockedSourceEffect;
+import mage.abilities.effects.common.continuous.BoostSourceEffect;
+import mage.abilities.effects.common.cost.CostModificationEffectImpl;
+import mage.abilities.hint.common.PartyCountHint;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.*;
+import mage.game.Game;
+import mage.players.Player;
+import mage.util.CardUtil;
+
+import java.util.UUID;
+
+/**
+ * @author TheElk801
+ */
+public final class SeafloorStalker extends CardImpl {
+
+    public SeafloorStalker(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{2}{U}");
+
+        this.subtype.add(SubType.MERFOLK);
+        this.subtype.add(SubType.ROGUE);
+        this.power = new MageInt(2);
+        this.toughness = new MageInt(3);
+
+        // {4}{U}: Seafloor Stalker gets +1/+0 until end of turn and can't be blocked this turn. This ability costs {1} less to activate for each creature in your party.
+        // TODO: Make ability properly copiable
+        Ability ability = new SimpleActivatedAbility(
+                new BoostSourceEffect(1, 0, Duration.EndOfTurn), new ManaCostsImpl<>("{4}{U}")
+        );
+        ability.addEffect(new CantBeBlockedSourceEffect(Duration.EndOfTurn).setText("and can't be blocked this turn"));
+        ability.addEffect(new InfoEffect(
+                "This ability costs {1} less to activate for each creature in your party. " + PartyCount.getReminder()
+        ));
+        this.addAbility(ability);
+        this.addAbility(new SimpleStaticAbility(
+                Zone.ALL, new SeafloorStalkerCostIncreasingEffect(ability.getOriginalId())
+        ).addHint(PartyCountHint.instance));
+    }
+
+    private SeafloorStalker(final SeafloorStalker card) {
+        super(card);
+    }
+
+    @Override
+    public SeafloorStalker copy() {
+        return new SeafloorStalker(this);
+    }
+}
+
+class SeafloorStalkerCostIncreasingEffect extends CostModificationEffectImpl {
+
+    private final UUID originalId;
+
+    SeafloorStalkerCostIncreasingEffect(UUID originalId) {
+        super(Duration.EndOfGame, Outcome.Benefit, CostModificationType.REDUCE_COST);
+        this.originalId = originalId;
+    }
+
+    private SeafloorStalkerCostIncreasingEffect(final SeafloorStalkerCostIncreasingEffect effect) {
+        super(effect);
+        this.originalId = effect.originalId;
+    }
+
+    @Override
+    public boolean apply(Game game, Ability source, Ability abilityToModify) {
+        Player controller = game.getPlayer(source.getControllerId());
+        if (controller != null) {
+            int count = PartyCount.instance.calculate(game, source, this);
+            CardUtil.reduceCost(abilityToModify, count);
+        }
+        return true;
+    }
+
+    @Override
+    public boolean applies(Ability abilityToModify, Ability source, Game game) {
+        return abilityToModify.getOriginalId().equals(originalId);
+    }
+
+    @Override
+    public SeafloorStalkerCostIncreasingEffect copy() {
+        return new SeafloorStalkerCostIncreasingEffect(this);
+    }
+}
diff --git a/Mage.Sets/src/mage/sets/ZendikarRising.java b/Mage.Sets/src/mage/sets/ZendikarRising.java
index f4615618652..2485631c88b 100644
--- a/Mage.Sets/src/mage/sets/ZendikarRising.java
+++ b/Mage.Sets/src/mage/sets/ZendikarRising.java
@@ -290,6 +290,7 @@ public final class ZendikarRising extends ExpansionSet {
         cards.add(new SetCardInfo("Sea Gate Colossus", 251, Rarity.COMMON, mage.cards.s.SeaGateColossus.class));
         cards.add(new SetCardInfo("Sea Gate Restoration", 76, Rarity.MYTHIC, mage.cards.s.SeaGateRestoration.class));
         cards.add(new SetCardInfo("Sea Gate, Reborn", 76, Rarity.MYTHIC, mage.cards.s.SeaGateReborn.class));
+        cards.add(new SetCardInfo("Seafloor Stalker", 78, Rarity.COMMON, mage.cards.s.SeafloorStalker.class));
         cards.add(new SetCardInfo("Sejiri Glacier", 37, Rarity.UNCOMMON, mage.cards.s.SejiriGlacier.class));
         cards.add(new SetCardInfo("Sejiri Shelter", 37, Rarity.UNCOMMON, mage.cards.s.SejiriShelter.class));
         cards.add(new SetCardInfo("Shadow Stinger", 123, Rarity.UNCOMMON, mage.cards.s.ShadowStinger.class));