diff --git a/res/card-pictures.txt b/res/card-pictures.txt
index 12317fc5a1c..2d8c7a8b411 100644
--- a/res/card-pictures.txt
+++ b/res/card-pictures.txt
@@ -38,6 +38,7 @@ snow_covered_mountain.jpg        http://www.wizards.com/global/images/magic/gene
 snow_covered_mountain1.jpg       http://www.wizards.com/global/images/magic/general/snow_covered_mountain.jpg
 snow_covered_mountain2.jpg       http://www.magickartenmarkt.de/img/cards/Ice_Age/snow_covered_mountain.jpg
 snow_covered_mountain3.jpg       http://www.magickartenmarkt.de/img/cards/Ice_Age/snow_covered_mountain.jpg
+khalni_hydra.jpg			http://www.wizards.com/global/images/magic/general/khalni_hydra.jpg
 avatar_of_might.jpg			http://www.wizards.com/global/images/magic/general/avatar_of_might.jpg
 avatar_of_fury.jpg			http://www.wizards.com/global/images/magic/general/avatar_of_fury.jpg
 eternity_vessel.jpg				http://www.wizards.com/global/images/magic/general/eternity_vessel.jpg
diff --git a/res/cards.txt b/res/cards.txt
index 5b8a679e37b..e06fd797b49 100644
--- a/res/cards.txt
+++ b/res/cards.txt
@@ -1,3 +1,10 @@
+Khalni Hydra
+G G G G G G G G
+Creature Hydra
+Khalni Hydra costs Green less to cast for each green creature you control.
+8/8
+Trample
+
 Drove of Elves
 3 G
 Creature Elf
diff --git a/src/forge/ComputerUtil.java b/src/forge/ComputerUtil.java
index 79ffa11714a..746c9cc3100 100644
--- a/src/forge/ComputerUtil.java
+++ b/src/forge/ComputerUtil.java
@@ -161,53 +161,77 @@ public class ComputerUtil
     Card originalCard = sa.getSourceCard();
     ManaCost cost = new ManaCost(sa.getManaCost());
     if(sa.isSpell() == true) {
-    if(originalCard.getName().equals("Avatar of Woe")){
-		String player = AllZone.Phase.getActivePlayer();
-		String opponent = AllZone.GameAction.getOpponent(player);
-        PlayerZone PlayerGraveyard = AllZone.getZone(Constant.Zone.Graveyard, player);
-        CardList PlayerCreatureList = new CardList(PlayerGraveyard.getCards());
-        PlayerCreatureList = PlayerCreatureList.getType("Creature");
-		PlayerZone OpponentGraveyard = AllZone.getZone(Constant.Zone.Graveyard, opponent);
-        CardList OpponentCreatureList = new CardList(OpponentGraveyard.getCards());
-        OpponentCreatureList = OpponentCreatureList.getType("Creature");
-        if((PlayerCreatureList.size() + OpponentCreatureList.size()) >= 10) {
-        	ManaCost cost2 = new ManaCost("B B"); 
+        if(originalCard.getName().equals("Avatar of Woe")){
+    		String player = AllZone.Phase.getActivePlayer();
+    		String opponent = AllZone.GameAction.getOpponent(player);
+            PlayerZone PlayerGraveyard = AllZone.getZone(Constant.Zone.Graveyard, player);
+            CardList PlayerCreatureList = new CardList(PlayerGraveyard.getCards());
+            PlayerCreatureList = PlayerCreatureList.getType("Creature");
+    		PlayerZone OpponentGraveyard = AllZone.getZone(Constant.Zone.Graveyard, opponent);
+            CardList OpponentCreatureList = new CardList(OpponentGraveyard.getCards());
+            OpponentCreatureList = OpponentCreatureList.getType("Creature");
+            if((PlayerCreatureList.size() + OpponentCreatureList.size()) >= 10) {
+            	ManaCost cost2 = new ManaCost("B B"); 
+            	cost = cost2;
+            }
+        } // Avatar of Woe
+        else if(originalCard.getName().equals("Avatar of Will")){
+    		String player = AllZone.Phase.getActivePlayer();
+    		String opponent = AllZone.GameAction.getOpponent(player);
+            PlayerZone OpponentHand = AllZone.getZone(Constant.Zone.Hand, opponent); 
+            CardList OpponentHandList = new CardList(OpponentHand.getCards());	        
+            if(OpponentHandList.size() == 0) {
+            	ManaCost cost2 = new ManaCost("U U"); 
+            	cost = cost2;
+            }
+        } // Avatar of Will
+        else if(originalCard.getName().equals("Avatar of Fury")) {
+    		String player = AllZone.Phase.getActivePlayer();
+    		String opponent = AllZone.GameAction.getOpponent(player);
+          PlayerZone OpponentPlay = AllZone.getZone(Constant.Zone.Play, opponent); 
+          CardList OpponentLand = new CardList(OpponentPlay.getCards());	   
+          OpponentLand = OpponentLand.getType("Land");
+          if(OpponentLand.size() >= 7) {
+          	ManaCost cost2 = new ManaCost("R R"); 
+        	cost = cost2;        	
+          }
+      } // Avatar of Fury
+        else if(originalCard.getName().equals("Avatar of Might")) {
+    		String player = AllZone.Phase.getActivePlayer();
+    		String opponent = AllZone.GameAction.getOpponent(player);
+          PlayerZone PlayerPlay = AllZone.getZone(Constant.Zone.Play, player); 
+          CardList PlayerCreature = new CardList(PlayerPlay.getCards());	   
+          PlayerCreature = PlayerCreature.getType("Creature");
+          PlayerZone OpponentPlay = AllZone.getZone(Constant.Zone.Play, opponent); 
+          CardList OpponentCreature = new CardList(OpponentPlay.getCards());	   
+          OpponentCreature = OpponentCreature.getType("Creature");
+          if(OpponentCreature.size() - PlayerCreature.size() >= 4) {
+          	ManaCost cost2 = new ManaCost("G G"); 
         	cost = cost2;
-        }
-    } else if(originalCard.getName().equals("Avatar of Will")){
-		String player = AllZone.Phase.getActivePlayer();
-		String opponent = AllZone.GameAction.getOpponent(player);
-        PlayerZone OpponentHand = AllZone.getZone(Constant.Zone.Hand, opponent); 
-        CardList OpponentHandList = new CardList(OpponentHand.getCards());	        
-        if(OpponentHandList.size() == 0) {
-        	ManaCost cost2 = new ManaCost("U U"); 
-        	cost = cost2;
-        }
-    } else if(originalCard.getName().equals("Avatar of Fury")) {
-		String player = AllZone.Phase.getActivePlayer();
-		String opponent = AllZone.GameAction.getOpponent(player);
-      PlayerZone OpponentPlay = AllZone.getZone(Constant.Zone.Play, opponent); 
-      CardList OpponentLand = new CardList(OpponentPlay.getCards());	   
-      OpponentLand = OpponentLand.getType("Land");
-      if(OpponentLand.size() >= 7) {
-      	ManaCost cost2 = new ManaCost("R R"); 
-    	cost = cost2;        	
       }
-  } else if(originalCard.getName().equals("Avatar of Might")) {
-		String player = AllZone.Phase.getActivePlayer();
-		String opponent = AllZone.GameAction.getOpponent(player);
-      PlayerZone PlayerPlay = AllZone.getZone(Constant.Zone.Play, player); 
-      CardList PlayerCreature = new CardList(PlayerPlay.getCards());	   
-      PlayerCreature = PlayerCreature.getType("Creature");
-      PlayerZone OpponentPlay = AllZone.getZone(Constant.Zone.Play, opponent); 
-      CardList OpponentCreature = new CardList(OpponentPlay.getCards());	   
-      OpponentCreature = OpponentCreature.getType("Creature");
-      if(OpponentCreature.size() - PlayerCreature.size() >= 4) {
-      	ManaCost cost2 = new ManaCost("G G"); 
-    	cost = cost2;
-  }
-  }
-    }   
+      } // Avatar of Might
+      else if(originalCard.getName().equals("Khalni Hydra")) {
+    		String player = AllZone.Phase.getActivePlayer();
+            PlayerZone PlayerPlay = AllZone.getZone(Constant.Zone.Play, player); 
+            CardList PlayerCreature = new CardList(PlayerPlay.getCards());	   
+            PlayerCreature = PlayerCreature.getType("Creature");
+            PlayerCreature = PlayerCreature.filter(new CardListFilter() {
+    			public boolean addCard(Card c) {
+    				return c.isCreature() && CardUtil.getColors(c).contains(Constant.Color.Green);
+    			}
+    		});       
+            String Mana = cost + " ";
+            if(PlayerCreature.size() > 0) {
+                for(int i = 0; i < PlayerCreature.size(); i++) {
+                	Mana = Mana.replaceFirst("G ", "");	
+                }
+                Mana = Mana.trim();
+                if(Mana.equals("")) Mana = "0";
+              	ManaCost cost2 = new ManaCost(Mana); 
+            	cost = cost2;
+            }
+        } // Khalni Hydra 
+        } // is Spell 
     ArrayList<String> colors;
 
     for(int i = 0; i < land.size(); i++)
@@ -282,53 +306,77 @@ public class ComputerUtil
     Card originalCard = sa.getSourceCard();
     ManaCost cost = new ManaCost(sa.getManaCost());
     if(sa.isSpell() == true) {
-    if(originalCard.getName().equals("Avatar of Woe")){
-		String player = AllZone.Phase.getActivePlayer();
-		String opponent = AllZone.GameAction.getOpponent(player);
-        PlayerZone PlayerGraveyard = AllZone.getZone(Constant.Zone.Graveyard, player);
-        CardList PlayerCreatureList = new CardList(PlayerGraveyard.getCards());
-        PlayerCreatureList = PlayerCreatureList.getType("Creature");
-		PlayerZone OpponentGraveyard = AllZone.getZone(Constant.Zone.Graveyard, opponent);
-        CardList OpponentCreatureList = new CardList(OpponentGraveyard.getCards());
-        OpponentCreatureList = OpponentCreatureList.getType("Creature");
-        if((PlayerCreatureList.size() + OpponentCreatureList.size()) >= 10) {
-        	ManaCost cost2 = new ManaCost("B B"); 
+        if(originalCard.getName().equals("Avatar of Woe")){
+    		String player = AllZone.Phase.getActivePlayer();
+    		String opponent = AllZone.GameAction.getOpponent(player);
+            PlayerZone PlayerGraveyard = AllZone.getZone(Constant.Zone.Graveyard, player);
+            CardList PlayerCreatureList = new CardList(PlayerGraveyard.getCards());
+            PlayerCreatureList = PlayerCreatureList.getType("Creature");
+    		PlayerZone OpponentGraveyard = AllZone.getZone(Constant.Zone.Graveyard, opponent);
+            CardList OpponentCreatureList = new CardList(OpponentGraveyard.getCards());
+            OpponentCreatureList = OpponentCreatureList.getType("Creature");
+            if((PlayerCreatureList.size() + OpponentCreatureList.size()) >= 10) {
+            	ManaCost cost2 = new ManaCost("B B"); 
+            	cost = cost2;
+            }
+        } // Avatar of Woe
+        else if(originalCard.getName().equals("Avatar of Will")){
+    		String player = AllZone.Phase.getActivePlayer();
+    		String opponent = AllZone.GameAction.getOpponent(player);
+            PlayerZone OpponentHand = AllZone.getZone(Constant.Zone.Hand, opponent); 
+            CardList OpponentHandList = new CardList(OpponentHand.getCards());	        
+            if(OpponentHandList.size() == 0) {
+            	ManaCost cost2 = new ManaCost("U U"); 
+            	cost = cost2;
+            }
+        } // Avatar of Will
+        else if(originalCard.getName().equals("Avatar of Fury")) {
+    		String player = AllZone.Phase.getActivePlayer();
+    		String opponent = AllZone.GameAction.getOpponent(player);
+          PlayerZone OpponentPlay = AllZone.getZone(Constant.Zone.Play, opponent); 
+          CardList OpponentLand = new CardList(OpponentPlay.getCards());	   
+          OpponentLand = OpponentLand.getType("Land");
+          if(OpponentLand.size() >= 7) {
+          	ManaCost cost2 = new ManaCost("R R"); 
+        	cost = cost2;        	
+          }
+      } // Avatar of Fury
+        else if(originalCard.getName().equals("Avatar of Might")) {
+    		String player = AllZone.Phase.getActivePlayer();
+    		String opponent = AllZone.GameAction.getOpponent(player);
+          PlayerZone PlayerPlay = AllZone.getZone(Constant.Zone.Play, player); 
+          CardList PlayerCreature = new CardList(PlayerPlay.getCards());	   
+          PlayerCreature = PlayerCreature.getType("Creature");
+          PlayerZone OpponentPlay = AllZone.getZone(Constant.Zone.Play, opponent); 
+          CardList OpponentCreature = new CardList(OpponentPlay.getCards());	   
+          OpponentCreature = OpponentCreature.getType("Creature");
+          if(OpponentCreature.size() - PlayerCreature.size() >= 4) {
+          	ManaCost cost2 = new ManaCost("G G"); 
         	cost = cost2;
-        }
-    } else if(originalCard.getName().equals("Avatar of Will")){
-		String player = AllZone.Phase.getActivePlayer();
-		String opponent = AllZone.GameAction.getOpponent(player);
-        PlayerZone OpponentHand = AllZone.getZone(Constant.Zone.Hand, opponent); 
-        CardList OpponentHandList = new CardList(OpponentHand.getCards());	        
-        if(OpponentHandList.size() == 0) {
-        	ManaCost cost2 = new ManaCost("U U"); 
-        	cost = cost2;
-        }
-    } else if(originalCard.getName().equals("Avatar of Fury")) {
-		String player = AllZone.Phase.getActivePlayer();
-		String opponent = AllZone.GameAction.getOpponent(player);
-      PlayerZone OpponentPlay = AllZone.getZone(Constant.Zone.Play, opponent); 
-      CardList OpponentLand = new CardList(OpponentPlay.getCards());	   
-      OpponentLand = OpponentLand.getType("Land");
-      if(OpponentLand.size() >= 7) {
-      	ManaCost cost2 = new ManaCost("R R"); 
-    	cost = cost2;        	
       }
-  } else if(originalCard.getName().equals("Avatar of Might")) {
-		String player = AllZone.Phase.getActivePlayer();
-		String opponent = AllZone.GameAction.getOpponent(player);
-      PlayerZone PlayerPlay = AllZone.getZone(Constant.Zone.Play, player); 
-      CardList PlayerCreature = new CardList(PlayerPlay.getCards());	   
-      PlayerCreature = PlayerCreature.getType("Creature");
-      PlayerZone OpponentPlay = AllZone.getZone(Constant.Zone.Play, opponent); 
-      CardList OpponentCreature = new CardList(OpponentPlay.getCards());	   
-      OpponentCreature = OpponentCreature.getType("Creature");
-      if(OpponentCreature.size() - PlayerCreature.size() >= 4) {
-      	ManaCost cost2 = new ManaCost("G G"); 
-    	cost = cost2;
-  }
-  }
-    }
+      } // Avatar of Might
+      else if(originalCard.getName().equals("Khalni Hydra")) {
+    		String player = AllZone.Phase.getActivePlayer();
+            PlayerZone PlayerPlay = AllZone.getZone(Constant.Zone.Play, player); 
+            CardList PlayerCreature = new CardList(PlayerPlay.getCards());	   
+            PlayerCreature = PlayerCreature.getType("Creature");
+            PlayerCreature = PlayerCreature.filter(new CardListFilter() {
+    			public boolean addCard(Card c) {
+    				return c.isCreature() && CardUtil.getColors(c).contains(Constant.Color.Green);
+    			}
+    		});       
+            String Mana = cost + " ";
+            if(PlayerCreature.size() > 0) {
+                for(int i = 0; i < PlayerCreature.size(); i++) {
+                	Mana = Mana.replaceFirst("G ", "");	
+                }
+                Mana = Mana.trim();
+                if(Mana.equals("")) Mana = "0";
+              	ManaCost cost2 = new ManaCost(Mana); 
+            	cost = cost2;
+            }
+        } // Khalni Hydra 
+        } // is Spell
     ArrayList<String> colors;
 
     for(int i = 0; i < land.size(); i++)
diff --git a/src/forge/Input_PayManaCost.java b/src/forge/Input_PayManaCost.java
index d4fb508c97b..34d00cda1fd 100644
--- a/src/forge/Input_PayManaCost.java
+++ b/src/forge/Input_PayManaCost.java
@@ -37,7 +37,7 @@ public class Input_PayManaCost extends Input {
             manaCost = new ManaCost("B B");   
 	        } else {
 	            manaCost = new ManaCost(sa.getManaCost());	        	
-	        }
+	        } // Avatar of Woe
         } else if(originalCard.getName().equals("Avatar of Will")) {
 			String player = AllZone.Phase.getActivePlayer();
 			String opponent = AllZone.GameAction.getOpponent(player);
@@ -47,7 +47,7 @@ public class Input_PayManaCost extends Input {
             manaCost = new ManaCost("U U");   
 	        } else {
 	            manaCost = new ManaCost(sa.getManaCost());	        	
-	        }
+	        } // Avatar of Will
         } else if(originalCard.getName().equals("Avatar of Fury")) {
 			String player = AllZone.Phase.getActivePlayer();
 			String opponent = AllZone.GameAction.getOpponent(player);
@@ -58,7 +58,7 @@ public class Input_PayManaCost extends Input {
             manaCost = new ManaCost("R R");   
 	        } else {
 	            manaCost = new ManaCost(sa.getManaCost());	        	
-	        }
+	        } // Avatar of Fury
         } else if(originalCard.getName().equals("Avatar of Might")) {
 			String player = AllZone.Phase.getActivePlayer();
 			String opponent = AllZone.GameAction.getOpponent(player);
@@ -70,13 +70,37 @@ public class Input_PayManaCost extends Input {
 	        OpponentCreature = OpponentCreature.getType("Creature");
 	        if(OpponentCreature.size() - PlayerCreature.size() >= 4) {
             manaCost = new ManaCost("G G");   
+	        } else {
+	            manaCost = new ManaCost(sa.getManaCost());	        	
+	        } // Avatar of Might
+        } else if(originalCard.getName().equals("Khalni Hydra")) {
+			String player = AllZone.Phase.getActivePlayer();
+	        PlayerZone PlayerPlay = AllZone.getZone(Constant.Zone.Play, player); 
+	        CardList PlayerCreature = new CardList(PlayerPlay.getCards());	   
+	        PlayerCreature = PlayerCreature.getType("Creature");
+	        PlayerCreature = PlayerCreature.filter(new CardListFilter() {
+				public boolean addCard(Card c) {
+					return c.isCreature() && CardUtil.getColors(c).contains(Constant.Color.Green);
+				}
+			});       
+	        String Mana = originalManaCost + " ";
+	        if(PlayerCreature.size() > 0) {
+                for(int i = 0; i < PlayerCreature.size(); i++) {
+                	Mana = Mana.replaceFirst("G ", "");	
+                }
+                Mana = Mana.trim();
+                if(Mana.equals("")) Mana = "0";
+	            manaCost = new ManaCost(Mana);
 	        } else {
 	            manaCost = new ManaCost(sa.getManaCost());	        	
 	        }
-        } else {
+        } // Khalni Hydra 
+        // For all other Spells
+        else {
         manaCost = new ManaCost(sa.getManaCost());
-        }
-    } else {
+        } 
+    } // isSpell
+        else {
     	manaCost = new ManaCost(sa.getManaCost());
     }
     }