The Doctor is the former leader of the Amadeus Syndicate in Metal Slug Attack. The Doctor has the exact same sprites and animation as Dr Amadeus; however he is not to be mistaken as him according to Another Story from Metal Slug Attack where the Professor was trying to find the legendary Dr Amadeus and he mistakes the Doctor as Amadeus since the Doctor tells him that Amadeus is a long gone lengend who's work was highly respected among the Syndicate.
- White Baby (Prototype) and Iron Fortress have both refered to the Doctor as "daddy"
- The Doctor was first introduced in Metal Slug Attack's story missions. He can be also found as an independent army unit called the Brave Guerrier where he commanders the Amadeus weapons from a control module