Chibimoth (ちびもす, Chibimosu) is a secondary character in Rewrite, and is Kotori's pet. He appears near the end of the Common Route and has a reccuring role in Kotori's route. Although Kotori claims he is a dog, Kotarou and many other characters frequently comment that he looks nothing like a normal dog. Chibimoth has exceptional strength and speed, despite his small stature. His catchphrase is "Mosu! Mosu!" and he uses it regularly.
In his dog form, Chibimoth has spiky pink fur, a short tail with a tuft of white fur, floppy ears with black fur at the ends, brown eyes, and a black nose.
In his familiar form his fur is a slightly darker pink, and he has tusks and a trunk. resembling those of a mammoth.
Chibimoth is very loyal to Kotori and is on fairly good terms with Kotarou. Unlike most minor familiars, he does express emotions occasionally, such as the fear he exhibited when saw the Earth Dragon for the first time, and when Chihaya called him delicious and wanted to eat him.
His loyalty stems from the fact that all familiars are loyal to summoners who have entered into a contract with them.
Pero was a dog abused by his previous owner, who cut off his ears and fed him onions, which are poisonous to dogs. As a result he was sensitive and nervous when eating his food, in case there were onions hidden in it. As a result, he preferred dry food because it would be more difficult to sneak onions in. The abuse left him permanently mistrustful, so even when he was adopted by Kotori and her family, he disliked them and even bit Kotori on occasion. One time when Kotarou came across Kotori, Pero bit Kotarou's foot without warning. However Kotori pleaded with Kotarou not to harm him. Eventually Pero released his foot. Kotori then explained the situation of Pero's previous abuse, and how it was her job to take care of him now. One day, Pero went missing, and Kotori revealed to Kotarou that she was relieved not to have to take care of him anymore, as she wouldn't have to keep trying so hard and wouldn't be growled at or bit anymore. But Kotarou later stumbled across Pero and after considering kicking him aside, he delivered him back to the Kanbe house, where Kotori was glad but disappointed with the outcome at the same time. Pero did not live much longer after those events, and his corpse was transformed into a familiar by Kotori, therefore becoming Chibimoth.
Chibimoth meets Kotarou in the forest when Kotarou goes looking for Kotori. After a few moments, he loses interest in him and walks away.
Later on, he is introduced to Kotarou as Kotori's dog, capable of performing several commands. Kotarou and Kotori then use him to beat up thugs in alleys, supposedly to "teach them a lesson." Winter Fang stopped them soon after.
Chibimoth comes across Kotarou's unconscious body up in the forest after he was attacked by the Leaf Dragon, and carries him to Kotori's Workshop. When Kotarou becomes Kotori's assistant, Kotori orders him to spar with Kotarou daily so that Kotarou can become stronger. At one point he and the Key get into a fight over a stick they pick up at the same time, only stopping when Kotarou makes them. When the Key later escapes the barrier around the workshop, Kotori orders Chibimoth to help Kotarou search for her. They then stumble upon the Earth Dragon in a battle against Guardian's hunters; they watch as dragon kills the hunters and leaves.
As they prepare to leave, Chibimoth is pierced by a branch thrown by Imamiya. When Imamiya tries to kill Kotarou, Chibimoth tackles him, grabs Kotarou with his trunk and the Key with his tusks, and flees the scene. Upon returning to the barrier, Chibimoth gradually begins to die from his wounds. At Kotarou's request, Kotori severs his feeling of pain in order to ease his suffering, as Kotori and Kotarou say their final goodbyes, Chibimoth barks like a dog, then turns to sand. This bark should have been impossible for him as a familiar, but shows that some part of him did recognize Kotori as more than just his summoner and master.
Chibimoth appears shortly before Kotarou meets the Earth Dragon in the forest. He is already mortally wounded when he appears, and lets out a quiet "Mosu" as he subsequently turns to sand.
- Camouflage: Chibimoth is able to disguise himself so that other people see him differently. This is why, even though he goes around in his mammoth form all the time, most people looking at him see him as a dog. The only exception to this is Kotarou, whose abilities allow him to sometimes catch glimpses of supernatural phenomena.
- Speed and Strength: Chibimoth possesses unnaturally high speed and strength, despite his size. Kotori mentions that the larger the familiar, the more burden movement puts on the summoner. Therefore Chibimoth is ideal for her purposes, as anything larger would drain her of too much energy.
- Chibimoth's name comes from the words "chibi" and "mammoth", which means Little Mammoth in Japanese.
- Perro is a Spanish word for dog.