diff --git a/Shared/World.cs b/Shared/World.cs
index d752231..b305f43 100644
--- a/Shared/World.cs
+++ b/Shared/World.cs
@@ -28,7 +28,7 @@ namespace SemiColinGames {
     public static Terrain WaterL = new Terrain('~', false, Textures.Grassland, 9, 2);
     public static Terrain WaterR = new Terrain('`', false, Textures.Grassland, 10, 2);
     public static Terrain Block = new Terrain('X', true, Textures.Ruins, 2, 0);
-    public static Terrain Spike = new Terrain('^', true, Textures.Grassland, 11, 8);
+    public static Terrain Spike = new Terrain('^', true, Textures.Grassland, 11, 8, true);
     public static Terrain Wood = new Terrain('_', true, Textures.Grassland, 10, 3);
     public static Terrain WoodL = new Terrain('(', true, Textures.Grassland, 9, 3);
     public static Terrain WoodR = new Terrain(')', true, Textures.Grassland, 12, 3);
@@ -54,16 +54,16 @@ namespace SemiColinGames {
     public TextureRef Texture { get; private set; }
     public Rectangle TextureSource { get; private set; }
 
-    private Terrain(char symbol, bool isObstacle, TextureRef texture, int x, int y) {
+    private Terrain(char symbol, bool isObstacle, TextureRef texture, int x, int y) :
+        this(symbol, isObstacle, texture, x, y, false) {}
+
+    private Terrain(char symbol, bool isObstacle, TextureRef texture, int x, int y, bool isHarmful) {
       if (mapping.ContainsKey(symbol)) {
         throw new ArgumentException("already have a terrain with symbol " + symbol);
       }
       mapping[symbol] = this;
       IsObstacle = isObstacle;
-      // TODO: don't hard-code just the one spike.
-      if (symbol == '^') {
-        IsHarmful = true;
-      }
+      IsHarmful = isHarmful;
       Texture = texture;
       int size = World.TileSize;
       TextureSource = new Rectangle(x * size, y * size, size, size);