The Lizard Man Heroes is the 4th light novel volume in the Overlord series. It was released on July 31, 2013. It details about the Lizardmen trying to save their tribe against the undead forces from total annihilation at the Great Lake.
The Ruthless army of death approaches the peaceful village of the Lizardmen. To protect their tribe, and to survive with their beloved ones, the Lizardmen rise. Meanwhile, the large army of undead goes to battle for the "experiment" of Ainz. Their commander is the 5th Floor Guardian, Cocytus, ruler of the frozen glacier. Witness the world ruled by stern law of the jungle.
The story begins with Zaryusu Shasha waking up and thinking about the lizardmen current situation. They are in a really bad spot, there used to be seven tribes but because of food shortage a war between the tribes started which eventually led to the seven tribes becoming five. They also had to make laws about food gathering to make sure that the surviving tribes had enough food to live on. Still the lizardmen believe that the strongest should rule and survive and see's this occurrence as a natural thing in life. This morning however is interrupted when an undead creature appears and declares that within a few days their undead army will appear and kill all the lizardmen.
Zaryusu Shasha quickly volunteers to inform the other tribes in hope that they can face this enemy together. He leaves together with his pet and friend Rororo that is a four headed hydra. He first arrives at the Red Eyed tribe and there meets with Crusch Lulu who is their leading figure. The two of them quickly fall in love with each other and together they travel to the next tribe who is led by Zenberu Gugu. In order to follow Zaryusu, Zenberu wants to have a duel with him since he is the bearer of Frost Pain one of the four treasures of the lizardmen. After Zaryusu wins, Zenberu together with his tribe joins them and time is advanced to the day of battle.
In the Great Lakes, Cocytus is the one who has been sent from Nazarick to destroy the lizardmen and at his disposal he has been given five thousand undead as well as an undead magic caster named Iguva=41 created by Ainz himself. Cocytus has been explicit ordered to lead this army from the back giving out orders, and that he should not appear on the battlefield. Believing that his army which is more then twice the size of the lizardmen will easily win, Cocytus simply orders them to attack head on. To his shock the lizardmen turns out to be much stronger then he thought and it is clear to see that they are winning against the undead horde and in a last attempt to win Cocytus sends out Iguvua=41. After a fierce battle between the leaders of the lizardmen together with Rororo against Iguva, the undead horde is defeated. Cocytus is surprised at his defeat and ashamed at losing an undead created by Ainz, however he is deeply impressed by the bravery show by the lizardmen while returning to Nazarick in order to receive his punishment.
Upon his return he is scolded for his failure and is given the order to annihilate the lizardmen with a stronger army. However Cocytus asks if they could spare the lizardmen instead and make them as part of Nazarick. Ainz is happy at this development since he wanted the guardians to experience a real army battle and was also impressed with the lizardmen and he also wants them to join Nazarick. So he changes his order from annihilation to occupation and that as for Cocytus punishment for his failure is to be given control and responsibility over the lizardmen once they have submitted to Nazarick.
The day after the battle the lizardmen see's a new undead army has appeared surprised at how quickly a new army could be assembled and doubly so when they see the composition of the new army. While the undead army again seems to be composed of five thousands undead this army is completely different compared to the other army. The previous army had broken and rusty weapons and armor they were also very disorderly. This undead horde on the other hand is fully equipped with magical weapons and armor, not only that, each and every item seems to be a unique and powerful magic weapon. While one of the big kingdoms might be able to field an army fully equipped with magic weapon they would at most have weapons that were mass produced with a simple enchantment they could never deploy an army with such diverse enchantments and with each soldier seemingly holding a powerful weapon. If that was not enough the leader of this army cast only one spell and instantly froze the entire wetland into ice.
After that Gargantua appeared at the forest and threw a giant boulder between the two armies. The undead legion gathered close to the rock, raised their shields flatly above themselves before kneeling down. The other skeletons jumped on top of the raised shields, nimbly maintained their balance then, like the skeletons below, likewise raised their own shields. The skeletons approached the giant boulder at abnormal speed and the stairs made out of undead army units was finally completed. Following this, the other undead soldiers also began to move. These undead were even more impressive looking than the skeletons moments ago, and numbered approximately one hundred. In their hands were spears with a piece of cloth attached, like the kind used by horse-back spearmen. The crossed spears formed a single path leading directly to the large boulder. The death magic caster stepped on the path arranged by the undead, and following behind him were numerous figures who had seemingly appeared out of nowhere. Leading the path was the magic caster whose extent of true strength had reached unfathomable heights.
Seeing as the undead leader wants to parlay Zaryusu and his brother Shasuryu Shasha goes forth knowing that they have no chance to win against this enemy. They are then told by Ainz that he is impressed with their previous battle and has decided that he will instead of destroying them, make them submit to him instead. He also informs them that he previously only sent one of his servants Cocytus to do battle against them but that he was told not to fight himself. They are then given the condition that if they can defeat Cocytus in battle, Ainz will no longer bother them however if they lose or decide not to fight they must submit to him. Before Zaryusu leave, he ask Ainz why he froze the lake area to which he responds that he didn't want to get mud on his shoe's. Zaryusu then truly realizes that Ainz must be a powerful demon and they have no chance to win against him seeing as he would use such powerful magic that they could not even dream of using for such a reason.
With a heavy heart Zaryusu and Shasuryu returns to the lizardmen and informs them of what they have been told and seen. Knowing that they have no chance to win but still deciding that they must at least challenge this Cocytus, they pick out the fifty most elite warriors among the lizardmen and then goes to fight against him. Cocytus by just activating his passive skill it effect all the elite lizardmen are unable to move however only Zaryusu, Zenberu and Shasuryu are still able to fight. However they are no match for Cocytus and everyone is killed by his hands. Lulu having been told not to join the battle and to stay behind to lead the lizardmen kneels before Ainz and submits to him fearing that they will now be treated as slaves. Ainz instead responds that they will be treated fairly as subjects under his rule and that he will leave Cocytus to lead them, and agrees to revive Zaryusu in exchange that she spies on the lizardmen for him.
Zaryusu wakes up surprised to be alive as he knows that he was previously killed by Cocytus. He finds Ainz standing there with a magic item that has brought him back to life and the lizardmen kneeling around him revering him as if he was a god. The lizardmen having no god to pray to and only honoring their ancestors. Zaryusu quickly realizes that someone with power like Ainz can't be a magic caster or a demon, he must be a real God. As these thoughts circles around in his mind he collapses from exhausted for being brought back to life.
- Chapter 1: Departure
- Chapter 2: Gathering, Lizardman
- Chapter 3: Army of Death
- Chapter 4: The Dawn of Despair
- Chapter 5: The Freezing God
- Volume 4 Special Edition
- Main story remains quite the same. Just some 'daily life' parts of Nazarick are added in the Light Novel.