Healer

The Healer is a player character. While the concept of a healer is ubiquitous, parts of the healer’s game, such as the quest, are based on Greek legends. Nethack says of them:

I swear by Apollo the physician, and Aesculapius, and Health, and All-heal, and all the gods and goddesses, that, according to my ability and judgment, I will keep this Oath and this stipulation -- to reckon him who taught me this Art equally dear to me as my parents, to share my substance with him, and relieve his necessities if required; to look upon his offspring in the same footing as my own brothers, and to teach them this art, if       they shall wish to learn it, without fee or stipulation; and that by precept, lecture, and every other mode of instruction, I will impart a knowledge of the Art to my own sons, and those of my teachers, and to disciples bound by a stipulation and oath according to the law of medicine, but to none others. I will follow that system of regimen which, according to my ability and judgment, I consider for the benefit of my patients, and abstain from whatever is deleterious and mischievous. [...]               [ Hippocrates' Oath, translated by Francis Adams ]

PHYSICIAN, n. One upon whom we set our hopes when ill and our dogs when well. [ The Devil's Dictionary, by Ambrose Bierce ]

Strategy

 * Although healers have excellent HP growth, their fighting skills are very poor. A well trained pet can quickly surpass its owner in battle prowess.
 * Because healers start with a large quantity of gold, it is possible to purchase a lot of protection from the Minetown’s priest if they avoid gaining experience. A skilled (or lucky) player can loot Sokoban and reach Minetown’s temple without landing a single blow.
 * When a healer reaches about level three, he can reliably cast stone to flesh, which can convert boulders into huge chunks of meat. Without the threat of starvation, players can adopt a very cautious and slow playing style with no penalty.