Holder of the Indigo Pacifier, Mammon is a member of the elite assassination team known as the Varia. Possessing half of the Ring of Mist, he engages in battle with Chrome at Namimori High's gym. Despite nearly defeating Chrome, his fortune reverses when Mukuro takes control of Chrome’s body, leading to Mammon's defeat and the loss of his claim to the Ring of Mist.
In the Future arc, it is mentioned that Mammon has died. Prior to his fight, Reborn and Colonello express uncertainty about whether he is truly an Arcobaleno. Mammon then reveals his sealed Pacifier, stating that unlike his peers, he has been striving to break the Arcobaleno curse. Through extensive research, he developed a chain capable of masking the power of both Arcobaleno pacifiers and Vongola Rings.
Mammon possesses a unique ability to locate someone by sneezing into a piece of paper; the mucus or saliva on the paper forms a map to the target. Like Mukuro, he can also create illusions. His real name is Viper, and he has a black frog named Phantasma that rests on his head.
Mammon embodies the sin of Greed and is considered the false god of riches and avarice in Biblical texts.
