Some TMNT stuff really isn't for little kids.
Koya (こうや, Kōya) was Shredder's pet falcon, whom he used for reconnaissance. She was mutated sometime following City Fall and ambushed the Turtles and their friends at April's parents' farmhouse during the Northampton storyline. When she attempted to attack Elizabeth O'Neil, Michelangelo defeated her by smashing a motorcycle into her, and Leonardo drove her away by injuring her in a manner that would kill her if she did not seek medical attention.
Because of her strength and loyalty, she accompanied Shredder on some of his more sensitive missions, such as when he attempted to negotiate with General Krang. She also was present when the Foot Clan invaded Burnow Island, but she and Bludgeon were driven away by the terraformed atmosphere, believing that they had failed to protect their master.
In the Vengeance arc, Koya took part in the Gauntlet along with Bludgeon, Rocksteady and Bebop. Leonardo defeated her by slicing off her wing feathers, leaving her permanently unable to fly. After her defeat, Koya left New York City with Karai and Bludgeon. While Bludgeon was resigned to his newly-blind state and made the best of it, Koya raged about her inability to fly, and still desired revenge against Leonardo.
In Japan, Karai brought her on the mission to reclaim the Kira no Ken, where Koya struggled with her temper and self-pity. When the sword was found, Koya removed a small bird-shaped talisman from the same cave.
The talisman later had a strange effect on Koya, speaking to her and causing her to be struck by lightning. When she attacked the spirit in the talisman, she obtained spectral wings that allowed her to fly again.
She is expressive, and is frequently excited and eager to hunt down her prey, and often speaks of eating the Turtles. She is particularly hostile towards Leonardo, whom she saw as a traitor, and her hatred for him only intensified after he crippled her in the Gauntlet.
She and Bludgeon have a sibling-like relationship, and they look out for each other.
- Koya is specifically a brown falcon, a species native to Australia.
- She is partly inspired by the Japanese folktale of the Sworded Falcon, and is named after the village, Koya, that the falcon terrorized.
- She was meant to have blue eyes, to tie her into Leonardo's blue mask, but in the comic she has brown eyes.