A Simple Gardener
The Celestial Gardener is a near-identical twin of Arishem the Judge who was tasked with tending to the "evolutionary garden" called Earth.
Years after the death of their first Earth-born Caretaker, the mutant tyrant known as Apocalypse, he was on the far side of the black matter nucleus that protects our universe when he received a Caretaker signal coming all the way from a Starcore Station orbiting the Sun.
After effortlessly leaping over to the station, he confronted Genocide, the son of Apocalypse, who was more than prepared to take his father's place as Caretaker. After some consideration, the Gardener found him worthy of the role and gave Genocide a Celestial Death Seed.
But before the Gardener could equip him with the standard issue armor given to all Caretaker's upon the completion of their initiation they were attacked by the Apocalypse Twins: Uriel and Eimin Worthington, the children of Archangel and Ichisumi.
Using Thor's axe, Jarnbjorn, Uriel split the Celestial Gardener in half and killed him causing a massive disturbance in the natural order of the cosmos.
As the Gardener died, the curiosity he had originally felt towards the twins turned to sadness, sadness for the life it had tended for so long and for those who would suffer the consequences of their actions.
Age of Apocalypse (Earth-295)
On Earth-295, a different Celestial Gardener had been assigned to tend to Earth, which it did up until it was murdered by an unknown force.
The Gardener's armor remained sprawled out on top of the more forested regions of the Savage Land where plants had already begun to grow on its surface.
The X-Force of Earth-616 along with Dark Beast entered the armor in order to find a Celestial Life Seed that could reverse Archangel's transformation into the next Apocalypse, after a fierce battle with several drones that looked identical to the dead Gardener's colleagues, X-Force managed to escape from the body with the Life Seed.
The corpse of the Gardener was eventually destroyed along with the rest of Earth-295 during a Multiverse-wide crisis.