There have been several models of Mecha Sonic in various games of the series. Although universally known as Mecha Sonic in Japanese media, many of these models were not initially named in English-language media.
The model from Sonic the Hedgehog 2 for the Master System was referred to as the Silver Sonic in the Master System and English Game Gear manuals, and this name has occasionally been used for other models in the series. To differentiate from the Mecha Sonic from Sonic & Knuckles, the model from the Sonic the Hedgehog 2 for the Sega Mega Drive was referred to as Robo Sonic in the Lego Dimensions Sonic the Hedgehog Level Pack.
Sonic the Hedgehog 2 (8-bit)
Sonic the Hedgehog 2 (16-bit)
The second version of Mecha Sonic appears in the Death Egg Zone of Sonic the Hedgehog 2 for the Sega Mega Drive. In Lego Dimensions it is known as Robo Sonic. In the Archie Comics it is known as Silver Sonic.
Sonic & Knuckles
A redesigned Mecha Sonic appears as the boss several times during the Sky Sanctuary Zone of Sonic & Knuckles. Against Sonic, it pilots Eggman's Egg Mobile twice and battles once on foot. It is the final boss battle in Knuckles the Echidna's story, in which it uses the Master Emerald to power up into its Super State.
Sonic the Fighters
A model of Mecha Sonic, known as Mecha Sonic Model No.29, appears briefly in the opening cutscence of Sonic the Fighters. Unlike most versions of Mecha Sonic, it has the ability to transform into a rocket. It can be seen outside the Death Egg II before transforming into a rocket and flying away.
Sonic the Hedgehog Pocket Adventure
In the Archie Comics series, Mecha Sonic and Silver Sonic are distinct.
In his first appearance, Dr. Robotnik's Metal Sonic (the Sonic CD version) was mistakenly identified as Mecha Sonic, which was corrected in future appearances. However, after the character was revived as Shard, he was also designated the "original Mecha Sonic" to distinguish him from the Metal Sonic robots created by Dr. Eggman.
Mecha Sonic (Robian)
Robotnik managed to have Sonic captured by Nack the Weasel and roboticized and took control of Sonic in issue #39. Mecha Sonic, as he was called, was sent to Knothole, where he managed to defeat both Bunnie Rabbot and Knuckles, and continued to wreak destruction on the village, until the Freedom Fighters were left with only one option. In the Mecha Madness super-special, Knuckles roboticized himself, using a neural overrider to retain his will. Mecha Sonic and Mecha Knuckles fought to a standstill, until they were both sent spiraling towards Robotropolis, where their impact caused a nuclear explosion which severely damaged Mecha Sonic, and would have killed Mecha Knuckles had it not been for Sonic's regaining his will and throwing himself in front of Knuckles at the last minute. Afterward, Nicole managed to de-roboticize Sonic with the help of the magical protection conferred to him by his recently acquired one billionth power ring.
Mecha Sonic was able to fly and hover using thrusters in his shoes. He had hyper jet boosters, teleportation, laser blasts, twin wrist lasers and dramatically increased strength, and his computer brain gave him digital tracking and allowed him to do complex mathematical calculations in seconds. Mecha Sonic stood at 130 cm and weighed 170 kg.
Mecha Sonic reappeared for one issue when Sonic and Tails were robotized by the Bem to fight Dr. Robotnik and Snively (who had been transformed back into organics) in an experiment to determine whether or not organic Mobians were superior to roboticized ones. Sonic and Tails won the battle and were reverted to normal afterwards.
Silver Sonic v1.0
Silver Sonic was a separate robot appearing in Archie's Death Egg Saga mini-series, Sonic Quest. It was a gigantic, robotic version of Sonic with silver body, red/black eyes and powerful steel fists, which Sonic fought aboard the Death Egg. He defeated it by frying its electronics with the electricity from sliced cables. He later crawled inside and took control of it in to battle Robotnik in his Eggs-O-Skeleton battle armor. Sonic abandoned the shell when he escaped the Death Egg.
Silver Sonic v2.0
Silver Sonic v2.0 is a scaled down version of the Silver Sonic. It was sent to attack Station Square after the fight with Chaos. It proved to much for the Freedom Fighters, tough Sonic eventually destroyed him, and Nate Morgan reprogrammed it to be the cities' defender. When Eggman went back to retrieve it, it chased him out of town. When Shadow was sent to retrieve a chaos emerald, the robot attempted to attack him, but Shadow destroyed it with ease. The cover of Silver Sonic II's debut issue also referred to it as "Mecha Sonic".
Silver Sonic v3.0
Mecha Sonic (Post-Super Genesis Wave)
Silver Sonic (Post-Super Genesis Wave)
Sonic the Comic
Death Egg guardian
An unnamed robot based on the Death Egg version of Mecha Sonic from Sonic 2 appeared in the Sonic the Comic #6, "Attack on the Death Egg". It survived its first encounter with Sonic (in Sonic 2), but was easily defeated on Sonic's second visit.
The most common Sonic robots in Sonic the Comic continuity are the Metallix series. These are mostly based on Metal Sonic rather than Mecha Sonic, although one model based on the Mecha Sonic from the Sky Sanctuary Zone appeared in "Count Down to Disaster" in Sonic the Comic #49 and #50.
- The help file included with the initial PC port of Sonic the Hedgehog CD claims that some early material refers to Metal Sonic as Mecha Sonic. This could be referring to his early appearances in the Archie comic series, where he was misnamed.
- Numerous Mecha Sonic models referred to as Mark I, Mark II, Mark III, Mark IV and Mark V were going to appear in Sonic X-treme. The description for a battle with Mecha-Sonic noted it would be a battle for rings and that one of Mecha-Sonics abilities would be to "Magnify" to attract rings.
- An unnamed Sonic robot can be seen, deactivated, in a stasis tube in the Final Egg base in Sonic Adventure. Although untitled, the robot bears some resemblance to the Mecha Sonic seen in Sonic the Hedgehog 2. This design is used as the basis of Silver Sonic v2.0 in the Archie Comics.
- The Mecha Sonics from Sonic the Hedgehog 2 and Sonic the Hedgehog 3 & Knuckles show up in LEGO Dimensions along with Metal Sonic. In this game, the Sonic the Hedgehog 2 version is referred to as "Robo Sonic"