When an egg gets very, very old, it cracks and releases a small stinking cloud. If it happens to be carried by the player, the cloud centers on the player. When it is close to rotten, the player can throw it and it will release the stinking cloud wherever it shatters. (The chance of it releasing a stinking cloud increases with age, asymptotically towards 100% the older the egg is).

Attempting to eat an old rotten egg will create the stinking cloud on the player’s square.