Cocopo (ココポ) is a Hororon Bird that Rulutieh rides.
Cocopo's head is covered in white feathers, the body is dark gray and the tail is red with a black arrow pattern. A black, red and white tuft extends from her head. Her saddle is red with brown straps that secure it in place. She chirps like a pigeon mixed with quail sound.
Cocopo is a pack animal that Rulutieh uses to travel around and serve as battle companion. She has the ability to read its master's emotions. Cocopo is very protective towards Rulutieh, and doesn't stop until she beats her master's enemies to a pulp. Even Rulutieh is unable to stop her when she goes berserk.
According to Rulutieh, Cocopo doesn't easily trust others and always keeps her guard up near other humans. In game, when Haku accidentally bumps to Cocopo, the bird affectionately rubs her head against him. Rulutieh states that she has never acted this affectionately towards others.
In the game, Haku first meets with Cocopo when he accidentally bumps into her. Cocopo stares at him, begins to rub her head against him, chirping happily. When Haku begins to walk away, Cocopo start to follow him. He sprints to get away but she catches up to and happily sits on the top of him. Haku begs Rulutieh tell Cocopo to stand up, but the bird refuses. Only once Kuon arrives does Cocopo finally let Haku up. According to Kuon, Cocopo refused to let go of Haku because she likes him very much. The reason why Cocopo didn't listen to Rulutieh's pleas was because Cocopo considers her a friend, not a master.
In anime, Haku mistakes Cocopo for a talking bird, and compliments her very beautiful voice. Cocopo's blushing reaction suggests that she likes Haku very much at first sight. During their journey to the capital city (before they were stopped by Nosuri), Cocopo affectionately nuzzled Haku. To Haku 's dismay, even Rulutieh can't stop her and she's never seen Cocopo this affectionate towards other people. Cocopo is very protective towards people she cares. For example when Maroro tried to sit between Haku and Rulutieh, she kicks Maroro away. When the bandit leader spits at Haku, Cocopo attacks the bandits in a rage and chases them away.
Because of this, Moznu the bandit leader called Cocopo a "Nugwisomkami" (in game only). When the group meets Moznu once again when he tries to rob somebody's home, the bandit screams at the sight of Cocopo and runs away. The group chase the bandit to their camp. Moznu shouts not to let Cocopo near them because she is a Nugwisomkami. Moznu said that Cocopo was a demon, a god of misfortune, the devil because of her size and colors. Rulutieh defends her by saying that Cocopo just an normal Hororon Bird. This answer went into blaze of debate, Moznu explains that a normal Hororon bird was smaller and the colors are far more vivid. Hearing this explanation, Haku asked the group if what Moznu said is true, which end with silence from Kuon and Rulutieh.
Cocopo considers Rulutieh to be her friend and family, rather than her owner. She willingly fights for and defends Rulutieh if anyone is ever rude or disrespects her.
Cocopo likes Haku very much. Rulutieh is dismayed as she was unable to stop her from crushing Haku. Haku is the only person she shows affection to beside Rulutieh.
Cocopo first showed a natural hostility towards Mukkuru when Aruruu and Camyu visited Yamato. In the end, the two animals reconciled and ate together, along with sleeping together. When Mukkuru left for Tuskur, Cocopo was very sad and even waved goodbye to her friend. She attempted to meet and chase him when she spotted him in Tuskur but was instead led to Munechika's camp with the supplies. This event happened in anime only.
- Despite being a Hororon bird, she can't fly.