Frown Cat

Frown Cat is the mortal enemy of Smile Dog. Instead of making you horribly depressed, angry and suicidal, looking at Frown Cat for an extended period of time will make you laugh for about six hours until you pass out. You will then start laughing at completely inappropriate times (like funerals) and everyone will abandon you, and you will spend your remaining years in a tiny, cockroach-infested shack, before dying alone, cackling manically all the while.

The only known cure is to look at Smile Dog for ten minutes without blinking.