Zaryusu Shasha is a lizardman of the Green Claw Tribe, and he's the younger brother of its chieftain, Shasuryu Shasha. His scales are dark green and black charcoal in color. A very wise individual, he is also regarded as the strongest lizardman and he is the wielder of the magical blade Frost Pain, one of the few precious treasures the lizardmen possess.
Zaryusu is a traveler, which is the name given to a lizardman who left the village in order to explore the outside world, and has a crimson brand/tattoo on his chest which denotes his status as such. Travelers are very respected individuals among the lizardmen, but conversely they don't have a say in any important matters, which heavily implies they might be socially shunned.
He has a Hydra as a pet named Rororo. Zaryusu stumbled upon it during his travels after finding it had been abandoned by its mother. Rororo is actually a deformed Hydra, because it has only four heads, while normally hydras have six. Rororo regards Zaryusu as his parent and would do practically anything to protect him.
Zaryusu falls in love with Crusch Lulu the moment he meets her, and claiming it's love at first sight, he immediately proposes in marriage. She eventually reciprocated his feelings and just before the lizardmen's final battle, Crusch fearful that he might die asks him to impregnate her with his child.
Ainz proposed that the lizardmen fight for the right to their freedom in a duel against Ainz's champion, Cocytus. Due to the massive skill gap, he was among those killed by Cocytus, although it should be noted he was the last one to be slain. He is later resurrected when the lizardmen swear loyalty to Ainz.