Eathes is a Tao-wielding monkey (probably some variety of orangutan) and a comedic villain from the manga Black Cat. He is one of the most recent members of the Apostles of the Star. Eathes is able to copy and impersonate people, so that the Apostles can use their knowledge. Eathes ultimately reforms after being saved by Eve (one of the primary protagonists) during the final battle.
Eathes' power is called "Copy". He can send his ki outside his body to "touch" people, becoming able to transform into them and assume their appearance, voice, memories, knowledge and skills. Eathes is able to switch between his normal form and that of anyone he copied; and he copied many, many people. Even though he masters his power to the perfection, the transformations he uses are not always adapted to the foes he is facing. Moreover, it seems that striking him cancels his transformation. Being a monkey, he also has strength, speed and reflexes beyond human levels and animal instinct which comes in handy when he gets himself in a tricky situation.
Eathes is extremely (comically) conceited, being convinced that he is the most powerful among the Apostles of the Star, while he is in fact the only Apostle without real fighting skills. All the human memories and experience that he stole enabled him to understand and speak human language fluently, even when under his normal monkey form.
Eathes considers himself human but, while anthropomorphic, he remains unable to fully think and analyze things like a human. Doctor states that he is unable to use combine the different types of knowledge he stole to deduce and understand more. Also, he rarely reflects before jumping into action, and upon realizing what situation he got himself in he tends to rely on others or (try to) deceive people. Eathes is not stupid though, at least not following the regular standards, it is just that being primarily an animal he apprehends the world in a more direct way and cannot consider a possibility before being confronted to it.
When and under what circumstances did he obtained a power of Tao is never fully explained, but it is known that the Apostles of the Star sensed his power and brought him with them to make him drink Shinkito. It can be guessed that he originally was one of Doctor's laboratory animals.
Eathes first appears when the three main protagonists, Train Heartnet, Sven Vollfield and Eve visit Dr Tearyu Lunatic, the world's greatest expert in nanotechnology, whose help to turn Train back to normal; (as Train was transformed into a child by nanomachines). Unbeknownst to them, the Apostles of the Star visited Dr Tearyu few days earlier and asked her to create a type of nanomachines that would make Creed Diskenth immortal.
The following night, Echidna Pallas and Eathes barge into Dr Tearyu's house alongside several of the Apostles' soldiers, in order to get Tearyu's final answer. (Eathes remains in Echidna's shadow at first and is not fully seen.) As Tearyu refuses, Eathes steps out of the shadows and copies her, immediately turning into a perfect double, with all her intellect and knowledge about nanomachines. Because of this, the Apostles have no further need of the real Tearyu, and Echidna orders her soldiers to shoot her down. Sven saves her by fires at the soldiers, seemingly knocking them out, but it turns out that they wear special armours that protect them. The soldiers engage a fight against Sven and Eve, but Train enters the fray right after. Train turned back to normal thanks to Tearyu's advices and in the process, he gained the ability to charge his revolver "Hades" with electricity to turn it into a devastating "Rail Gun". He uses this newfound power to defeat the soldiers, prompting Echidna and Eathes to flee.
Eathes is next seen under Tearyu's shape, working alongside Doctor to create the nanomachines of immortality. (It is later revealed that it was Doctor who created them, by using Eathes' sterile knowledge.)
When Train, Sven, Eve invade the Apostles of the Star's manor on Clarken Island, Creed orders all his remaining followers not to hold back against them. Eathes confronts the protagonists shortly after Doctor's defeat. He stops several soldiers from attacking them, stating that he will get rid of them himself. The soldiers immediately comply, calling him "Sir Eathes" (much to Train's mirth) as he is a Tao-wielder. Eathes boasts about his power before assuming the shape of a wrestler to attack Train, who effortlessly knocks him away. Eathes then realizes that while the wrestler his very strong by human standards, he is by no mean a match for the legendary Black Cat. Should Eathes have turned into a mightier fighter or copied the protagonists themselves, he would have proven much harder to defeat.
Train then orders him to lead them to Creed's lair, to which he agrees, hoping to kill them from behind. En route to Creed's private quarters, they run into Kranz Maduke and Baldorias Fanghini, the Chrono Numbers IV and VIII. After a soldier that Eve protected from Number VIII blows himself up, misunderstanding her intention, the Chrono Number departs and the group reaches the midair bridge.There, they find Echidna and two Cyborgs from the Phantom Star Brigade (that Eathes does not know) waiting for them. Echidna orders the cyborgs to kill Sven, Eve and Eathes (whom she labels as a traitor) but allows Train to reach Creed. Eve then protects Eathes from a rocket fired by the Flying Cyborg, explaining that she fights to protect people, enemies included. After the Phantom Star Brigade is defeated Echidna teleports a grenade near Eve. However, Eathes saves her life by kicking the grenade away, in gratitude for saving his own life earlier.
Following Creed's defeat, Eathes departs and starts living under a human shape. He is seen in the last chapter walking in the streets under his wrestler form, (eating a banana to hint his identity) alongside Leon Elliott, another reformed Apostle.