The physical embodiment of the Ring of Gluttony.
In its first form as a ghost-like appearance, it did not have any defining attitude but was only gluttonous, and very cranky as it screamed loudly that all that were present in the school had heard the cry, much to their dismay. It was shown to have mellowed out thanks to Clara Valac's lullaby.
Alicred eventually gained intelligence, and with it came a playful personality. However, Alicred still holds its protective nature over Iruma.
(Source: Mairimashita! Iruma-kun Wiki)