Havel the Rock

Havel the Rock is a hostile character in Dark Souls.

Location
At the bottom of the tower before the Taurus Demon boss arena, the player can use the Watchtower Basement Key, or Master Key to find Havel waiting at the end of the final staircase.

Alternatively, the tower in which Havel is located can be accessed adjacent to the Hydra's area in Darkroot Basin. When using this entrance, which also requires one of the aforementioned keys, Havel will be waiting for the player at the right side from the door.

Plot
The Chosen Undead finds Havel automatically hostile with no dialogue whatsoever, suggesting that Havel has long since gone hollow. He wields Dragon Tooth, the legendary great hammer.

Havel's Ring can be obtained after his defeat, while the rest of his equipment; his armor, shield, and weapon, can be obtained in Anor Londo.

Lore
Havel the Rock was a close friend of Gwyn, and a general in what was presumably Gwyn's army. Havel was a steadfast and resilient man, inspiring his men to do great things. He and his warriors donned armor carved from solid rock and wore rings bestowing them with the ability to carry a heavier load.

Bishop Havel, as he is also known, despised magic users, thus creating the miracle Great Magic Barrier to counter them. Curiously though, his shield is mentioned to have been imbued with magic of its own. Havel had an intense hatred for Seath the Scaleless, grandfather of Sorcery, and was his sworn enemy.

Strategy
Havel is a very dangerous enemy, easily killing lower vitality players in one hit. His overhead attack can break through guards and inflict critical damage. Havel takes very low damage from most starting weapons and tools (aside from pyromancies and weapons buffed with Gold Pine Resin). Havel's predictable and slow attack patterns means that he is particularly susceptible to backstabs and parrying.

He is very evasive for a defensive NPC, favoring rolling when players use magic or ranged attacks. It may prove difficult to hit him if he decides to roll around a lot, as he has surprisingly good timing. A rapid series of rolls will, however, drain a majority of his stamina, so one or two kicks can easily break his guard if he's blocking with the Dragon Tooth.

He will not pursue the player very far beyond the threshold connecting to Darkroot Basin, providing a quick escape route if necessary.

Trivia

 * The descriptions of Havel's Ring and his armor set state that they were worn by his warriors and do not mention that they were worn by Havel himself, yet they do not state that Havel did not wear them.