Flattery (sometimes referred to among Slapeggs as Pumpkin-envy) is an Envy vice and a former Sin. He was raised to Sin status, unbeknownst to the other Sins, who strongly objected to Desire leaving. Coupled to that is that Flattery is quite adept to provoking ire and annoying others. Greed has a heartfelt dislike for Flattery, because Flattery's powers are similar, and Desire was his best friend even before they became Sins. Gluttony, on the other hand, does not seem to mind Flattery, as she has a tendency to eat his pumpkin head. Since it regenerates, she can eat it over and over again. She has described it as "so ripe, orange, juicy and full of nutrients", and this combination makes it irresistible to her. For his part, Flattery seems to take this very well, even describing it as "kind of hot" when Craving eats his head.
Flattery's head is detachable, allowing him to be used as a makeshift "envelope" for smuggling small objects. However, he claims that having to put the head on again hurts. He can still talk when the head is detached.
Flattery has a similar pervy personality to Desire, and he never shuts up.
After learning that he was left out during the Sin's adventures with Addison, Flattery quit without telling the Sins. This left the world in a severe state of imbalance during Marlowe's stint as Host, and caused Balance to get sick. Flattery was subsequently replaced by Jealousy.