Souka

Souka (lit. "Blue Flower") is Gabiru's younger sister and Abiru's daughter. As the nameless Lizardman Tribe Guard Captain, she is a green anthropomorphic lizard with violet hair, light armor, and a yellow scarf.

[Spoiler] After being named by Rimuru and evolving into a Dragonewt, she takes a more human appearance and wears ninja-like attire. She's also able to hide her wings and horns, which makes her perfect for infiltration missions as she is able to pass off as human. The color of her wings and horns is red after evolving. [/Spoiler]

(Source: Tensei shitara Slime Datta Ken Wiki)