When using Bastion's original skin, Ganymede's appearance is similar to a xanthochroic (i.e. yellow mutant) Northern cardinal, Cardinalis cardinalis. However, this bird species is native to North America, unlike Ganymede, who comes from Germany.
Ganymede's sex was confirmed to be male with the release of its plushie. However, it has features of both male (e.g., a crest, its singing behavior) and female (e.g., nest-building behavior) birds.
For a short time before the reactivation of Bastion, Ganymede built its home on the right shoulder of the omnic, who had been deactivated in the forest near Eichenwalde. Curious, the bird pecked constantly at its eye, leading to Bastion's awakening. After it noticed the robot walking away, Ganymede decided to follow Bastion as it traveled through the forest, heading to Stuttgart. Ganymede finally caught up with the robot in the rain, and the two of them decided to spend time exploring more of the forest.
After a while, Bastion and Ganymede rested in a clearing, and the bird decided to continue with its nest. Bastion picked up a twig and gave it for Ganymede, as an affection gesture. The two were then interrupted by a sound of a woodpecker, which alerted Bastion into believing it was the sound of gunshots. The tension went up to the point Bastion reverted into turret mode and destroyed a part of the forest, along with Ganymede's nest and scared the bird away.
Ganymede finally caught up with Bastion again, this time in battle mode, as it marched towards Stuttgart, planning to attack the city. Landing on the omnic's gun and leaving a twig there, Ganymede waited as Bastion was contemplating its choices. Finally, Bastion reverted to passive mode and picked up the twig.
Both of them then returned to the forest, as the robot abandoned its mission.
In Binary, Ganymede continues to stay by Bastion's side, even goes to the point of protecting it by carrying Torbjörn's net trap away to make sure the omnic wouldn't get captured. In the end, after Torbjörn decided to adopt Bastion, Ganymede is last seen following the two while in the air.
- The name of Ganymede may be based on a divine hero with the same name in Greek mythology who is described by Homer as the most beautiful of the mortals.
- Ganymede is also the name of one of Jupiter's moons, which is taken from the Greek mythology mentioned above.
- Ganymede's species changes based on Bastion's equipped skin.
- It becomes a red Northern cardinal (Cardinalis cardinalis) with the 'Omnic Crisis' skin.
- It becomes a blue jay (Cyanocitta cristata) with the 'Defense Matrix' skin.
- It becomes an unknown species of bird with orange coat with the 'Blizzcon 2016' skin.
- It becomes a crow with the 'Tombstone' skin.
- It becomes similar to a red junglefowl (Gallus gallus) with the 'Rooster' skin.
- It becomes similar to a red-naped sapsucker (Sphyrapicus nuchalis) with the 'Antique' skin.
- It becomes similar to an Arizona woodpecker (Leuconotopicus arizonae) with the 'Woodbot' skin.
- It becomes a rock pigeon for both the 'Gearbot' and 'Steambot' skins, but it is an albinistic animal in the latter case.
- It becomes a European robin for the 'Uprising' skin.
- In 'Steambot' and 'Gearbot' skins, Ganymede wears a tiny monocle on its left eye.