Siegmeyer of Catarina

Siegmeyer of Catarina is a character in Dark Souls. A jolly and polite (if somewhat bumbling) knight, Siegmeyer is a recurring NPC in Dark souls.

Location
He can be first found by the gate to Sen's Fortress before ringing both bells of awakening. After the bells are rung he will be at the first boulder encounter area. Once anor londo is reached he will be near the 3rd bonfire and if you kill all of the knights nearby he rewards you with a Tiny Being's Ring. After that he will be at the bonfire in Firelink Shrine, If you tell him it was you that opened the gate to Sen's Fortress he will again reward you with the Emit Force spell. He will later be found in Blighttown on one of the small patches of land amidst the poison swamp, if you give him 3 purple moss clump's he will reward you with the Pierce shield, the same shield he was wearing in Firelink. In Lost Izalith just after falling through the floor he will help you fight the demons below. Later in Ash Lake he will be dead and his daughter will reward you with a Titanite Slab.

strategy
If you battle him at the closed gate, he uses a big sword like the Bastard Sword. His sheild is specialised for parrying so don't attack him when he has his sheild up. He usually weilds his sword 2 handed amd will do overhead slashes. If you lure him to the bonfire you will find that theres a glitch which causes him to teleport back to his spot when he walks through the doorway. The best strategy is to poison him with some dung pie or other poison. Then you just wait by the bonfire while looking at his depleting health. You can speed it up by carefuly timing your attacks and attacking when he is recovering from his overhead slash.

Trivia

 * Siegmeyer seems to be underprepared for poison as he is seen pleading with the player to spare him some purple moss. However, when he later jumps into the pit in Lost Izalith to fight the tentacle demons there, he is shown immune to the effects of poison.