The Invader Soldier unit are Invaders that usually resembles a humanoid robots in a black suit, hat, dark glasses and holding a suitcase.
Combined together in Fusion Mode, they create the more powerful and larger versions of Invaders of which can take multiple forms like centipedes, balls, and fake highways. Their weakness is the Red Invader, who initiates the Fusion and if destroyed, will cause a similar chain reaction to the other Invaders in the same form. The Invaders are not human but they can take on the appearance of a human in the original series.