the belief in a diety and one diety only; Rat. rat is the creator of the universe and fucks little nigger children up the ass if they are bad. he restores order with his dildo of wife beating. he created earth by teleporting his rat workers from Rat heaven to the universe and thus created earth. Rat has been said to be seen on many occasions pissing on dead black people. he is said to have only a few followers but the followers are mainly gifted with herpes and transvestite hookers. Rat is said to come to Earth in the year 2050 when he will come back with his 7 trusty niggers and slay all the evil that stands before him. There is another diety that stands in the way of Rat, though, which is Tar, Rat's evil brother. But it is said that if you believe in Rat and follow him he will save you and repel Tar during the end times, but only if he has enough followers.
example of Ratism
Christian: Godis the only true way!
Rat: RAT IS THE ONLY ONE AND ONLY TRUE GOD FUCK YO COUCH