diff --git a/js/game.js b/js/game.js
index e900aba..8bb66b7 100644
--- a/js/game.js
+++ b/js/game.js
@@ -195,7 +195,7 @@ export class Cell extends Array {
     }
 
     has(name) {
-        return this.some(tile => tile.name === name);
+        return this.some(tile => tile.type.name === name);
     }
 
     try_leaving(actor, direction) {
diff --git a/js/tiletypes.js b/js/tiletypes.js
index e073f3b..bc2416e 100644
--- a/js/tiletypes.js
+++ b/js/tiletypes.js
@@ -135,6 +135,12 @@ const TILE_TYPES = {
     // Floors and walls
     floor: {
         draw_layer: DRAW_LAYERS.terrain,
+        on_arrive(me, level, other) {
+            if (other.type.name === 'blob' && other.previous_cell && other.previous_cell.has('slime')) {
+                // Blobs spread slime onto floor
+                level.transmute_tile(me, 'slime');
+            }
+        },
     },
     floor_letter: {
         draw_layer: DRAW_LAYERS.terrain,