Zweihander

The Zweihander is an ultra greatsword in Dark Souls.

Availability
Located on a corpse in the graveyard between the Firelink Shrine and The Catacombs behind three Skeleton Swordsman and one Giant Skeleton Swordsman.

Characteristics
Like other Ultra Greatswords, the Zweihander has very slow attack speed, and can leave players exposed if they miss their target. However, its early game availability and useful moveset make it very popular for high Strength builds both in PvE and PvP, especially in the Lightning or Fire upgrade paths.

The Zweihander's strong attack is its signature overhead swing. It doesn't deal quite as much damage as the strong attack of other Ultra weapons, but deals immense poise damage, and is much faster to swing (the other weapons require a "charge up"). Normal enemies will be immediately smashed into the ground, and almost all bigger enemies will be interrupted. It is one of the only moves in the game that can swing faster than a Mushroom Parent or Crystal Golem can attack, yet is guaranteed to break their poise, interrupting their attack. This makes it an ideal weapon/attack versus those enemies. Like most weapons with large poise breaking capacities, barely missing an enemy with the strong attack can still cause a stagger.

The overhead swing also has the advantage of a high vertical reach. This makes it a very good weapon to use to cut Dragon tails: Most other ultra greatswords will require a running attack to swing upwards, and great hammers don't reach quite as high.

Trivia

 * The Zweihander is a Germanic greatsword originating in the Middle Ages. It was originally crafted to cleave a knight and his horse at the same time, reducing the risk of missing. It's name in German literally translates to "two-hander", referencing the fact that it's great weight and length require it to be wielded with both hands.
 * The length below the two appendages above the crossguard is a blunt part of the blade known as the ricasso, which can be held and serves to shorten the wielders grip. This technique is known as half-swording, and provides better control and leverage when fighting in close quarters.
 * The aforementioned appendages are designed to deflect blades away from the hand of anyone using this technique.