Metal Sonic Mark III, Metal Sonic Wiki

Metal Sonic Mark III was an upgrade of Metal Sonic which would have appeared in Sonic X-Treme. It changed Metal (or Mecha) Sonic's appearance to be taller and red and also gave him two spear/pile-bunker-like arms. It only has one spine, and also has shoulder & knee pads.

Sonic Adventure 2 - Wikipedia

Neo Metal Sonic (Archie), Sonic Wiki Zone

Metal Sonic v2.5, Metal Sonic Wiki

Metal Sonic v3.0, Sonic Wiki Zone

Metal Sonic v1.0, Metal Sonic Wiki

Metal Sonic, Sonic Wiki Zone

Rocket Metal Sonic (Adventures), Sonic Fanon Wiki

Sonic the Hedgehog (IDW) (Comic Book) - TV Tropes

Captain Metal, Sonic Wiki Zone

Metal Sonic vs Emerl

I get confused with their names. : r/SonicTheHedgehog

Hyper Metal Sonic, Sonic Wiki Zone