The Butcher (and any nearby monsters on level two which you haven't cleared out yet)
The Butcher's Cleaver (single-player game)
Random magic item (multiplayer game)
This is a tough quest early in the game. His lair is a square room on the second floor of the dungeon and is easily recognized by all of the impaled bodies inside the room. If you are capable of casting and can afford a Stone Curse spell, the quest is very easy - cast it and chop away until he's history. But very few players will be able to cast Stone Curse early in the game, and unless you have a high dexterity or an item which gives you a magical fast attack or fast recovery, it is difficult to go toe-to-toe with the Butcher. A Bear weapon (which forces him back) makes it possible to take him head-on.
A better plan, however, may be to open the door to his lair, wait until he says FRESH MEAT and then flee to any nearby location (it helps to map out an escape route first) with a door and a chain link wall. Go through the door and shut it before he follows you in, and you'll be able to hit him with projectile weapons and spells until he finally goes down (which may take a while). You can greatly speed up the process if you are capable of casting a Firewall spell. Cast it right through the grating, and he will gleefully stand in the flames until he fries. (If you happen to replay a dungeon with an advanced character and are capable of casting a Golem spell, do so. It is more than a little amusing to watch the Golem take about two seconds to plow through the Butcher.)
After the Butcher dies, he will leave behind his Cleaver. It makes a nice weapon for a low-level character, although it is prone to break easily.
The Butcher (and any nearby monsters on level two which you haven't cleared out yet)
The Butcher's Cleaver (single-player game)
Random magic item (multiplayer game)