Mainframe Ghost

Mainframe Ghost is a legendary skin from the Circuitry collection. It's drawn for the classic (Steve) model with 4-pixel arms, so choose that arm type when you apply it.

The palette is a dark green circuit-board top and dark green legs. Look for glowing eyes on a dark face. Download the 64×64 PNG, then upload it under Skins in the Minecraft Launcher for Java Edition, or import it from the Dressing Room in Bedrock Edition.