Major Metallitron

Major Metallitron (aka Sergeant Metallic) is an android created by the Red Ribbon Army.  He is one of the guards of Muscle Tower, assigned to defeat anyone who tries to get past him.  He is also one of the first to discover that Goku is an alien, after performing a bio-scan on him.

He is voiced by Bill Capizzi in Harmony Gold's dub of Mystical Adventure, Chris Rager in FUNimation's in-house dub, Lucas Gilbertson in the Blue Water dub, and Paul Bandey in the AB dub's version of Mystical Adventure.