Katze Plains

Katze Plains (カッツェ平野) is a large plain that is considered a barren land for numerous undeads to spawn at.

Background
Surrounded by a permanent foggy atmosphere, the Katze Plains were once a large open plain that was inhabited by people but eventually it became a battle ground where the armies of both Re-Estize Kingdom and Baharuth Empire choose to fight their annual battles. Now it is nothing more than a large empty plain surrounded by a permanent fog that blankets the whole area with a few old buildings scattered around and in ruin due to numerous fights both between the nations as well as people fighting countless undead.

A notable feature of this place is that due to high amount of casualties sustained by both sides every year in their annual war, the place has become a hot spot for undead creatures to spawn. This ranges from zombies to skeleton warriors and even Skeletal Dragons. Another particular trait is that the fog that surrounds the plains registers as a form of lifeforms and as a result detection magic against undead is useless to use in this area and many people fell prey to ambushes from the undead spawn as a result. There is also an infamous Elder Lich who haunts the plains on a Ghost Ship that sails the mists that forms frequently in that area.

Many adventurers stationed themselves in E-Rantel due to the Katze Plains, this is because it is a valuable location as a source of income for them as they can kill monsters for money without ever running out. Not only that there have expeditions to fetch certain undead monsters from time to time so they will be sold to fight in the Empire's Arena.

The Invaders of the Large Tomb Arc
About five years prior to the current events, scouts from the Baharuth Empire patrolling the area discovered a new form of undead that has never been encountered in this place before and many soldiers were sent to deal with it but most ended up being killed by it. Fluder Paradyne and his disciples were sent in to deal with the problem and managed to weaken it enough for it to be captured. The undead was transported to the capital of the Empire, imprisoned deep within the vaults of Fluder's magic academy for further research.

The Magic Caster of Destroy Arc
It was here yet again that the Re-Estize Kingdom and the Baharuth Empire engaged in one of their annual wars like before. However, this time around the forces of Nazarick, under the direct command of Ainz Ooal Gown, participated as fellow allies of the Empire. As a result, the outcome of their battle against the Kingdom was a decisive victory for the alliance. The aftermath and casualties of the war are the complete decimation of the Royal Army including the loss of their strongest warrior, Gazef Stronoff.

The Ruler of Conspiracy Arc
Though the Sorcerer Kingdom has claimed the Katze Plains as part of its territory, the Sorcerer King has yet to consolidate his power over the area as he turns to other matters in building his country's foundations.

The full results of the aftermath of the battle were finally made clear, the Re-Estize Kingdom lost over 180,000 of their 260,000 men who were in the militia, with most of the remaining survivors suffering mental damage and nightmares of the horrors that they saw. In addition, the Crown Prince Barbro was missing along with the 5,000 soldiers that were sent to escort him during their investigation of Carne Village.

Meanwhile, the Baharuth Empire also suffered losses of their own during the battle as 143 men lost their lives during the stampede from running away from the Dark Young. In addition, nearly 4000 men decided to leave the Knight Corps and at least 200 of them had suffered mental illness in the aftermath of the war. Which mean that over 6% of the 60,000 men sent to the plains were removed from service without actually doing anything in their part.

Layout
The Katze Plains is encompassed by a thick, dense fog. The fog blankets the plains all year round. For some reason whenever the two countries come to fight, the fog lifts up as if to welcome them for the new dead to arrive and it also registers as a life form by magic casters who analyze it, implying the fog itself to be some form of sentient entity.

Known Inhabitants
The Katze Plains is a haunted place better known as the Death Ground for many old and new forms of undead monsters to appear, such as the recent Death Knight encounter by soldiers from the Baharuth Empire five years ago. In other words, these types of various monsters that are known to have spawn or at least inhabit this area or some part of it like the mention of a Ghost Ship so far would include:
 * Elder Lich
 * Death Knight
 * Skeleton Warrior
 * Skeletal Dragon
 * Soul Eater
 * Squire Zombie
 * Zombie

Trivia

 * In the Web Novel, the Lich Captain of Katze Plains swears fealty towards Ainz upon meeting him.
 * The many undead that spawned at the Katze Plains would be cleared for the annual war between the Baharuth Empire and the Re-Estize Kingdom.
 * The Plains in the past were once habitable and had various settlements but the constant warfare and spawning of undead forced everyone to abandon it.
 * The Empire would deploy forty-thousand troops on the plains while the Kingdom would likewise deploy two-hundred thousand troops during their annual war.