The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story. The introduction shows that the Ellimist is telling his story to an unnamed Animorph, foreshadowing the events of the final book of the series, and fulfilling the promise that one Animorph would die after being visited by the Ellimist.
As an unnamed Animorph lies on the brink of death, the Ellimist appears and recounts to him/her his origins as Azure Level, Seven Spar, Extension Two, Down-Messenger, Forty-One (Toomin) the Ketran and his transfiguration into the Ellimist as a final request to the dying Animorph. The Ketran race was virtually extinguished by the Capasins, who had seen transmissions of violent virtual Ketran games that had been broadcast into space and mistook them for a violent species that meddled with other ones. Toomin/Ellimist was one of the few survivors. These survivors became space nomads, seeking a replacement for their home Ket. Toomin became the leader of this group and was the only survivor when it crash-landed on a mostly aquatic moon. His mind was absorbed and kept alive at the bottom of the sea by a moon spanning entity known as Father that absorbed the information in the brain (or equivalent) of every corpse on it. After defeating Father at music, Toomin began to grow too intelligent for Father and defeated him, incorporating all the memories of corpses on the moon, eventually becoming a blending of minds.
After he defeated Father he began to wander the universe without purpose until he started to resolve conflicts and crises under the name Ellimist. The Ellimist worked like this for several thousand years until he encountered the Crayak, who existed to destroy all life in galaxies, a strong antithesis to what the Ellimist had come to stand for. Crayak engaged Ellimist in games that had entire planets at stake. Ellimist did not fare well and lost far more often than he won. Losing motivation to continue fighting the Crayak, the Ellimist temporarily retreated to the Andalite home planet, possibly beginning his worship as an Andalite god. (The Ellimist created an Andalite body for himself after taking bits and pieces of memories from himself and all the people he knew and loved, thus created the Andalite race in his own image.) The Andalites at the time were not the advanced civilization but a primitive collection of tribes. By living on the planet as an Andalite, the Ellimist learned that the key of survival was to create as many offspring as possible; although so many die, with repeated efforts life could multiply faster than the Crayak could wipe them out. With a renewed vigor, the Ellimist fought the Crayak, creating the Pemalites, creators of the Chee, who spread quickly throughout the galaxy (until they were destroyed by Crayak's own creations, the Howlers). Although, the Crayak eventually destroyed the Ellimist physically by luring him into a black hole, the Ellimist found himself fully integrated into the fabric of space-time. Soon, both the Crayak and the Ellimist recognised direct combat to be much too dangerous for themselves and space-time itself. To prevent such catastrophic damage, the Crayak and the Ellimist agree to construct the intricate "game" they are seen to play in the Animorphs series.