Koko is Boko's friend in Final Fantasy V. The two chocobos meet in Pirates' Hideout and have several chocobo babies together. She is first met by the Warriors of Light at the Chocobo Forest in the Second World, although Bartz points that she cannot be mounted due to her gender.
In the external minigame for Final Fantasy VIII on the Pocket Station, Chocobo World, Koko is once again Boko's love interest. Their paths first cross during Boko's quest to find MiniMog. Throughout Boko's journey their paths continue to cross until Koko herself is kidnapped by the Demon King, which incites Boko to go and rescue her.
Every time Boko and Koko interact, Boko's power increases, which results in a more powerful chocobo summon in Final Fantasy VIII.
In the quiz game Brain Blast one of the possible questions refers to Koko: The Yellow Bird is a story about a chocobo living on Gran Pulse. What is the name of the heroine? The answer is "Coco", alternative spelling of Koko. Tamed chocobos can also be named this alternate spelling.
- In the Dawn of Souls and 20th Anniversary remakes of the original Final Fantasy, Koko is one of the automatic names the player can choose for the Black Mage job.
- Bartz says that Koko cannot be ridden because she is female. However, in Final Fantasy VII, chocobos of both genders can be ridden, and in Final Fantasy VIII, it is implied that all of the rideable chocobos are female (as they are identified by the Chocoboy as being the mothers of the chicobos).