From Sonic Retro

ZERO SAdvance2.PNG
First seen: Sonic Adventure (1999)
Species: Eggman robot (E-100 Series)
Gender: N/A

ZERO, known very occasionally as E-100α[1] or E-100 Alpha (E-100 アルファ)[2], is a villainous Eggman robot which debuted in Sonic Adventure. Possibly some sort of prototype for the E-100 Series, ZERO is a large green and black robot with red eyes that vaguely resembles a trash can with arms.


ZERO as it appears in Sonic Adventure.

In Sonic Adventure, ZERO functions as the principal foil in Amy Rose's story. The robot spends the game chasing a blue bird named Birdie (known as Lily in Sonic X) who had taken refuge with the pink hedgehog. ZERO chases Amy around Station Square, finally catching up in Twinkle Park. After being imprisoned in the Egg Carrier, Amy escapes with help from E-102 Gamma and wanders into the Hot Shelter, where ZERO found her and started chasing her again. Even after Dr. Eggman had already taken the bird's Chaos Emerald and the Egg Carrier had crashed into the ocean, ZERO persistently continued its directive to chase Amy while she was searching for the bird's parents in Final Egg.

The robot functions not just as a plot device, but also as a persistent threat within Action Stages themselves, following Amy around each of her levels, and more often than not is Amy required to avoid it by using stealth or simply running away. She can attack ZERO to push it back, but hitting it too many times will make it enter an "overdrive" mode which makes Amy's attacks ineffective.

ZERO is unequivocally destroyed by Amy in the boss battle at the end of her story. Despite this, and perhaps as testament to the crazed, psychedelic rules that hold sway in the Special Zone, the robot reappears in Sonic Advance 2 as the guardian of that game's Special Stages. Here, ZERO is known simply as "Dr. Eggman's Guard Robot".Media:SonicAdvance2 GBA US manual.pdf[3]

Boss Fight - "ZERO"

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Main article: ZERO (boss)

In other media

Archie comics

In the Sonic the Hedgehog comic series by Archie Comics, there were multiple E-100 Alpha units that were created for unspecified reasons to capture a green Flicky in issue #81. Amy would confront one of them to help the Flicky, and summon her Piko Piko Hammer for the first time to destroy the robot, but was then captured by two other E-100 Alpha units and taken to the Egg Carrier.

The E-100 Alphas were later decommissioned and scrapped.

Sonic X

In Sonic X, ZERO appeared during the Chaos Saga, where its role is largely the same as in Sonic Adventure: capturing Amy and Lily and bringing them aboard the Egg Carrier.

Connection to the E-100 Series

ZERO is never referred to as an E-100 Series robot, or as "Alpha", in Sonic Adventure or its associated strategy guides. However, the name "E-100 Alpha" is canonical, appearing in Amy's section on the Japanese-language Sonic Adventure Dreamcast homepage. The name Alpha also appears on the less-defunct Japanese Sonic Channel page for Gamma.[2]

During the opening cutscene of Gamma's story, Eggman calls him "the second of my E-100 robots". Since E-101 Beta is the other one, this implies that Eggman does not consider ZERO to be a true E-100 model. Additionally, unlike the other E-100 Series robots, there is no animal organic battery inside ZERO when it explodes after the boss fight.


  1. htt (Wayback Machine: 2003-02-26 14:35)
  2. 2.0 2.1 (Wayback Machine: 2019-05-26 17:20)
  3. File:SonicAdvance2 GBA US manual.pdf, page 23
Dr. Eggman's E-100 Series of Robots
E-100 Alpha | E-101 Beta (Mk II) | E-102 Gamma | E-103 Delta | E-104 Epsilon | E-105 Zeta | E-121 Phi | E-123 Omega | Egg Keeper

Characters in the Sonic the Hedgehog game series
Recurring characters
Heroes Sonic (Super, Hyper, Darkspine, the Werehog, Excalibur) | Tails (Super) | Knuckles (Super, Hyper) | Amy Rose | Cream | Big | Blaze (Burning) | Silver (Super) | Sticks
Anti-heroes/Neutrals Shadow (Super) | Rouge | Espio | Charmy | Vector | Mighty (Super) | Ray (Super) | E-102 Gamma | E-123 Omega | Jet | Wave | Storm
Villains Dr. Eggman | Metal Sonic (Rocket, Neo, 3.0) | Fang | Chaos (Perfect) | E-Series | ZERO | Eggman Nega | Orbot | Cubot | Deadly Six (Zavok, Zazz, Zomom, Master Zik, Zeena, Zor)
Teams Sonic/Heroes | Rose | Dark | Chaotix | Babylon
Other Animals (Flicky) | Froggy | Chao (Hero, Dark) | Tikal | Pachacamac | Omochao | Gerald & Maria Robotnik | President | Cheese | Chocola | Vanilla | G.U.N. Commander | Wisps
One-off characters
Heroes Emerl | Marine | Lumina Flowlight | Chip | Shahra | Knights of the Round Table | Caliburn | Yacker | Avatar
Anti-heroes/Neutrals Bean | Bark | Shade | Merlina
Villains Witchcart | Battle Kukku Army (15th, 16th, Dr. Fukurokov) | Tails Doll | Metal Knuckles | E-101 Beta | Void | Biolizard | G-merl | Black Doom | Shugo-hei | Iblis | Mephiles | Solaris | Erazor Djinn | Captain Whisker | Johnny | Master Core: ABIS | Ix (Super) | Dark Gaia | King Arthur | Hard Boiled Heavies | Infinite
Other Illumina | Elise | Duke of Soleanna | Coconut Crew | Vikings | Professor Pickle | Wentos | Don Fachio | Dodon Pa | Heavy | Bomb | Tiara Boobowski | Honey