Eggman has apparently discontinued the production of these robots for unknown reasons. Although they are referred to as androids (or robots, in one case), E-123 Omega implied they were actually created via cloning and thus were at the very least biomechanical.
The Shadow Androids made their debut in Sonic Heroes during Team Dark's story, though it was never actually stated to be such. A Shadow Android that was severed from the waist down was discovered by Shadow shortly after the team defeated a fake Eggman, with Rouge also expressing concern for Shadow. This discovery led to Shadow wondering if he was a robot as well.
They made another appearance in the ending of Team Dark's story. After the trio had defeated Dr. Eggman and his Egg Emperor (Metal Sonic disguising as Eggman), Rouge the Bat went in search of the Doctor's rumored treasure trove on the flagship of the Egg Fleet. What she actually found was a room packed with row after row of Shadow Androids suspended in tubes just like the one she had discovered the real Shadow in. E-123 Omega then walked in and stated his intention to destroy the entire place, but before he could do so, he revealed to a distraught Rouge that the Shadow Androids were part of a cloning project by Eggman. He said that the original must exist somewhere as there is no way anyone could make Shadow Androids without the real Shadow. With this new information, Rouge left Omega to his work. Whether Omega successfully destroyed the room and its Shadow Androids or got side-tracked after the Metal Overlord appeared is unknown.
Besides the Shadow Androids in Team Dark's story, they also made an implied appearance in the Bullet Station level of Team Chaotix's story. During the level, their mysterious client (who is the real Dr. Eggman) had given them a mission to destroy all the capsules before they could be delivered to the Egg Fleet. The capsules design bore strong resemblance to the capsules used to contain the Shadow Androids seen in Team Dark. Why Eggman would order Team Chaotix to destroy the capsules is never explained, although it can be inferred that he saw it as a viable alternative to Metal Sonic (who had at that point gone renegade) making use of the Shadow Androids for its own purposes.
They first appeared in the Iron Jungle, where Shadow came face-to-face with a troop of them while they were receiving their orders from Eggman about how to take care of the Black Arms. The Shadow Androids mainly appeared within rooms of the Iron Jungle base and attacked the real Shadow in groups of three and later tried to assist Eggman when he battled Shadow and Omega in his Egg Breaker. They later tried to keep Shadow out when he infiltrated Eggman's Lava Shelter in his new quest to destroy Eggman.
If the player performs the Neutral Dark or Neutral Hero stories, Shadow is convinced that he is an android. While Shadow is facing Black Doom in his Devil Doom form, however, Eggman says that he used a robot to rescue Shadow after he fell from the Space Colony ARK in Sonic Adventure 2, meaning that while Shadow was in a stasis tube, Eggman was making Shadow Androids.
In the multiplayer mode of Shadow the Hedgehog's self-titled game, six Shadow Androids are playable. They all claimed to be the real Shadow, and that the others were fake.
Two of them look identical to Shadow, with one of them having yellow marking as opposed to red. The others were silver, resembling Metal Sonic, but with different stripe colors ranging from blue, orange, pink, and green. Two of them have a modified grenade launcher and the other two had rapid-fire machine-guns. These weapons are non-removable, but have infinite ammunition.
The androids can activate Dark Shadow and all of its normal effects and attacks, just like the real Shadow. Hero Shadow is available, but is almost useless, as it simply flies you around the stage (usually through loops and tunnels).
The Shadow Androids appear do not have the ability of speech. However, the Multiplayer Androids of Shadow the Hedgehog were able to speak. The ones that can speak all similarly mimic the real Shadow by calling other Shadow Androids "fakers."
Powers and abilities
Shadow Androids seem to have all the physical capabilities of Shadow and can withstand more damage than the average Egg Pawn. They fire tracer missiles from their hands (similar to how Shadow can launch Chaos Spears from his hands) and can defend themselves from physical attack by jumping and mimicking the Homing Attack, so the only way to defeat them is with a weapon or the Spin Dash. The Shadow Androids seem to be the only enemies that Shadow encounters that are resistant to punches or kicks.
The multiplayer Shadow Androids can move at great speed just like Shadow. The ones that look more organic can use a variety of weapons, while the metal ones have unlimited ammunition in the form of bullets and explosive shells. The colors of the Androids can be red like Shadow, or tangerine. The robotic Shadow Androids can range from a color such as pink, blue, green, and orange. However, the robotic Androids cannot pick up any weapons, as the weapon they use is merged into their arm, disabling the use to pick up another weapon. Also the Shadow Androids appear to talk identically to the real Shadow unlike many other of Eggman machines like Metal Sonic, E-123 Omega and E-102 Gamma. ( E-102 "γ")
Differences between the real Shadow and the Shadow Androids
The androids' skin is darker than that of the real Shadow.
The androids' muzzle is smaller than Shadow's.
The androids' overall physical traits are more jagged and angled in appearance.
The androids' rings are smaller and darker than Shadow.
The Shadow androids (excluding the multiplayer models) cannot speak.
Some androids are differently colored.
Shadow Androids could be analogous to Shadow as Metal Sonic is analogous to Sonic except Shadow Androids look exactly like Shadow.
They are also similar to the Virtual Hedgehogs introduced in the Wii version of Sonic Colors.
A broken Shadow Android
Rouge entering a room full of Shadow Androids.
Identical Shadow Androids.
Shadow looking up at a Shadow Android.
A yellow Shadow Android.
A blue Shadow Android with a machine-gun arm attached for combat.
A pink Shadow Android with a machine-gun arm attached for combat.
A green Shadow Android with a modified grenade launcher attached on its arm.
An orange Shadow Android with a modified grenade launcher attached on its arm.