Quilp is one of Dickens's most reprehensible villains. Dickens describes his nasty smile as "appearing to be the mere result of habit and to have no connexion with any mirthful or complacent feeling." He adds: “The creature appeared quite horrible with his monstrous head and little body.”
Joseph Clayton Clark,"Kyd." The Characters of Charles Dickens. London: Raphael Tuck, 1890.