Lero is a specialized golem that belongs to the Millennium Earl and the Noah clan. It appears as a normal cane umbrella with a small, talking jack-o-lantern on the tip that serves as its head. Despite its unassuming form, Lero possesses considerable magical power, though it only uses these abilities when commanded by the Earl. On one occasion, it transforms into a sword for the Earl to wield during an encounter with Allen Walker after Allen's evolution into Crown Clown. Lero is neurotic and easily nervous, often becoming upset over minor disturbances. However, when operating behind enemy lines, it reveals a more sadistic side, openly taunting the exorcists. It also has the habit of ending nearly every sentence with the word Lero. Within the Noah family, Lero is frequently used as a plaything by Road Kamelot. Lero's primary role in the story is as a companion and tool for the Earl, providing both comic relief and occasional utility in battle. The character does not undergo significant development or change over the course of the series, remaining a constant if minor presence tied to the Earl's side.