diff --git a/Mage.Sets/src/mage/cards/s/SeaTroll.java b/Mage.Sets/src/mage/cards/s/SeaTroll.java
new file mode 100644
index 00000000000..09a364ec860
--- /dev/null
+++ b/Mage.Sets/src/mage/cards/s/SeaTroll.java
@@ -0,0 +1,118 @@
+package mage.cards.s;
+
+import mage.MageInt;
+import mage.MageObjectReference;
+import mage.abilities.Ability;
+import mage.abilities.condition.Condition;
+import mage.abilities.condition.OrCondition;
+import mage.abilities.costs.mana.ManaCostsImpl;
+import mage.abilities.decorator.ConditionalActivatedAbility;
+import mage.abilities.effects.common.RegenerateSourceEffect;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.CardType;
+import mage.constants.SubType;
+import mage.constants.WatcherScope;
+import mage.constants.Zone;
+import mage.game.Game;
+import mage.game.events.GameEvent;
+import mage.game.permanent.Permanent;
+import mage.watchers.Watcher;
+import mage.watchers.common.BlockedAttackerWatcher;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
+/**
+ *
+ * @author noahg
+ */
+public final class SeaTroll extends CardImpl {
+
+    public SeaTroll(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{2}{U}");
+        
+        this.subtype.add(SubType.TROLL);
+        this.power = new MageInt(2);
+        this.toughness = new MageInt(1);
+
+        // {U}: Regenerate Sea Troll. Activate this ability only if Sea Troll blocked or was blocked by a blue creature this turn.
+        Ability ability = new ConditionalActivatedAbility(Zone.BATTLEFIELD, new RegenerateSourceEffect(), new ManaCostsImpl("{U}"), new SeaTrollCondition());
+        ability.addWatcher(new SeaTrollWatcher());
+        this.addAbility(ability);
+    }
+
+    public SeaTroll(final SeaTroll card) {
+        super(card);
+    }
+
+    @Override
+    public SeaTroll copy() {
+        return new SeaTroll(this);
+    }
+}
+
+class SeaTrollWatcher extends Watcher {
+
+    private final Set<MageObjectReference> blockedOrBlockedByBlueThisTurnCreatures;
+
+    public SeaTrollWatcher() {
+        super(SeaTrollWatcher.class.getSimpleName(), WatcherScope.GAME);
+        blockedOrBlockedByBlueThisTurnCreatures = new HashSet<>();
+    }
+
+    public SeaTrollWatcher(SeaTrollWatcher watcher) {
+        super(watcher);
+        this.blockedOrBlockedByBlueThisTurnCreatures = new HashSet<>(watcher.blockedOrBlockedByBlueThisTurnCreatures);
+    }
+
+    @Override
+    public void watch(GameEvent event, Game game) {
+        if (event.getType() == GameEvent.EventType.BLOCKER_DECLARED) {
+            MageObjectReference blocker = new MageObjectReference(event.getSourceId(), game);
+            MageObjectReference attacker = new MageObjectReference(event.getTargetId(), game);
+            if (blocker.getPermanentOrLKIBattlefield(game).getColor(game).isBlue()){
+                blockedOrBlockedByBlueThisTurnCreatures.add(attacker);
+            }
+            if (attacker.getPermanentOrLKIBattlefield(game).getColor(game).isBlue()){
+                blockedOrBlockedByBlueThisTurnCreatures.add(blocker);
+            }
+        }
+    }
+
+    @Override
+    public void reset() {
+        super.reset();
+        blockedOrBlockedByBlueThisTurnCreatures.clear();
+    }
+
+    public boolean blockedOrBlockedByBlueCreatureThisTurn(MageObjectReference creature){
+        return blockedOrBlockedByBlueThisTurnCreatures.contains(creature);
+    }
+
+    @Override
+    public SeaTrollWatcher copy() {
+        return new SeaTrollWatcher(this);
+    }
+}
+
+class SeaTrollCondition implements Condition {
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        Permanent sourcePermanent = game.getPermanentOrLKIBattlefield(source.getSourceId());
+        if (sourcePermanent != null){
+            SeaTrollWatcher watcher = (SeaTrollWatcher) game.getState().getWatchers().get(SeaTrollWatcher.class.getSimpleName());
+            if (watcher != null) {
+                return watcher.blockedOrBlockedByBlueCreatureThisTurn(new MageObjectReference(sourcePermanent, game));
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return "{this} blocked or was blocked by a blue creature this turn";
+    }
+}
\ No newline at end of file
diff --git a/Mage.Sets/src/mage/sets/Homelands.java b/Mage.Sets/src/mage/sets/Homelands.java
index 2c8cc628746..c679a8f3101 100644
--- a/Mage.Sets/src/mage/sets/Homelands.java
+++ b/Mage.Sets/src/mage/sets/Homelands.java
@@ -149,6 +149,7 @@ public final class Homelands extends ExpansionSet {
         cards.add(new SetCardInfo("Rysorian Badger", 96, Rarity.RARE, mage.cards.r.RysorianBadger.class));
         cards.add(new SetCardInfo("Samite Alchemist", 117, Rarity.COMMON, mage.cards.s.SamiteAlchemist.class));
         cards.add(new SetCardInfo("Sea Sprite", 38, Rarity.UNCOMMON, mage.cards.s.SeaSprite.class));
+        cards.add(new SetCardInfo("Sea Troll", 39, Rarity.UNCOMMON, mage.cards.s.SeaTroll.class));
         cards.add(new SetCardInfo("Sengir Autocrat", 56, Rarity.UNCOMMON, mage.cards.s.SengirAutocrat.class));
         cards.add(new SetCardInfo("Sengir Bats", "57a", Rarity.COMMON, SengirBats.class, NON_FULL_USE_VARIOUS));
         cards.add(new SetCardInfo("Sengir Bats", "57b", Rarity.COMMON, SengirBats.class, NON_FULL_USE_VARIOUS));