Qwilleran (Qwill to his friends) is a man who goes from late forties to mid fifties over the course of the series. He's six feet, two inches tall, with dark brooding eyes and salt-and-pepper hair (he can still claim that it's mostly pepper). He is slightly overweight in the early books, but loses some weight over the course of the series. He is often described as looking melancholy or brooding, but he is witty and enjoyable company. His most distinguishing feature is his "luxuriant moustache," which is considered attractive by many women, and Polly Duncan describes it as being similar to the composer Edward MacDowell’s. (Elsewhere it is compared to those of Mark Twain - who is alleged to have visited Moose County in 1895 - and Charles Rennie Mackintosh.) However, his moustache is more than mere facial hair. Whenever Qwilleran gets a suspicion that something is wrong or his instincts are right, he will get "a tingling sensation on his upper lip." Depending upon the strength of the sensation, he may be seen "stroking it with his fingertips" to "pounding mustache with his knuckles".