Epsilon (known as Photar in the 1980s series' English dub) is a recurrent character in Astro Boy who appears as a rival to Pluto. Epsilon is shown to be from Australia alongside Hercules of Greece, Gerhardt of Germany, and North #2 of Scotland.


Original Manga

Epsilon appeared in Volume 3 of the original manga, more specifically in the “The Greatest Robot on Earth” story arc. Here, he hails from Australia and was eventually defeated, like the others, except for Astro.

1980s series

Epsilon caring for the children

In the 1980s series, Epsilon has an androgynous personality and is once again a member of the World's Greatest Robots. He first appears in Episode 24, The Greatest Robot in the World (Part 1). He comes from “the Southern Continent” and acts as a caregiver for the kindergarten children. He was originally going to defeat Pluto, however, he decided to save a child who was about to get crushed under a tree, hence leaving him defenseless and was eventually defeated by Pluto.

It must be noted that Pluto chose a rainy day to fight, since this would leave Epsilon weak as he is a photon-powered robot.

He is shown to be Australian (referred to as the 'Southern Continent'). His location is shown to be near Uluru (Ayers Rock), possibly within the Alice Springs area.

2003 series

Epsilon reappeared in the 2003 series as a secondary protagonist. The character went through a major character redesign and is now portrayed as female, marking this as the first time Astro has a female robot as an ally. She was first introduced in the episodes The Rise of Pluto and The Fall of Acheron, where she is shown to be an environmentalist and protects Metro City's wildlife and greenery, even bravely stopping a tornado in its tracks. She is one of the robots Pluto challenges, and during battle, heads in the water where she has an advantage instead of fighting on land where the advantage would be given to Pluto. She is there shown to be able to detect ocean currents. However, a pod of dolphins spoils her plan and as she, displaying her environmental concern, rushes to save them, Pluto senses her weakness and swims to a highly volcanic area - if Epsilon shoots and misses (which is a high probability), hundreds of marine creatures will be killed. She eventually deems this probability and does not shoot; therefore Pluto shoots her and renders her immobile. However, strangely, Pluto did not destroy her like he destroyed his other opponents.

Epsilon reappears in the episode Escape from Volcano Island, where she is a nominee for the prestigious Robot of the Year Award (alongside Astro, Harley, an unnamed robot nurse, and unnamed robot computer hacker). However, the terrorist Kato, as well as Mr. Drake, ensure the cruise doesn't go as planned when they wreak havoc, allow the ship to stray off course, and allow a volcano to erupt. While the robots hurriedly start to attempt to turn the ship back, Epsilon and Astro fly off to destroy some of the flying debris so it will not harm the ship. Their efforts are found to be futile, and to make matters worse, the ship is going to crash on the island. In the nick of time, the ship is hacked into and turned around. Meanwhile, Astro uses his arm cannon to ensure the ship has a clear path. Eventually, all five robots receive the award because of their sheer bravery.

Epsilon would once again receive a prominent role, this time in the Robotonia episode Showdown in Robotonia. Reno and Hannah have stolen Yuko's car and are now attempting to contact Duke Red's forces but do not succeed, as the car is broken. Suddenly, enemy forces surround - and prepare to destroy - the car with them in it, as they are leagued with the robots. Epsilon appears from underneath the car and starts to get the car hovering. They escape followed by the human forces. Epsilon predicts that the ice wall in front of them will collapse, so they hurriedly go under it and it does collapse, causing the human forces to lose them. Eventually, the message does go through and the humans realize their mistake. Unfortunately, the war isn't over because the robots refuse to surrender.

Alongside various characters who have appeared throughout the series, Epsilon's final appearance was in Astro Reborn amongst the group of characters who were showing support for Astro when he was being rebuilt.


In the Japanese version of the 1980s series, he is voiced by Hidetoshi Nakamura.

Being in 'The Greatest Robot in the World' story arc, the 2003 series Pluto episodes are merely remakes of the 1980s series' episodes, which is in turn a remake of the original manga's. For this reason, most of the robots Pluto fights are simply remakes. For more information, refer to this table: