The Laughing Door (笑いのトビラ, Warai no Tobira) is an event in Tomba! 2: The Evil Swine Return.
Get access to a laughing door.
In order to enter a laughing door and clear the event, Tomba must be in the status ailment laughing, that can be achieved by eating a red laughing fruit in the Crying Laughing Forest.
Once Tomba have gained the status ailment, approach a laughing door to open it. The event is now cleared.