Dr. Geo Mandrake was a scientist responsible for allying Bahamut to research Red Falcon's DNA. He also planned the construction of the cybernatic super-soldier Lucia, but was unable to finish her after he died.
In here he is a non-player character who you have to escort. He has a health bar and it can run out.
According to the manual to Contra: Hard Corps, He was involved in making biological weapons during the Alien Wars.
In here he is a scientist who works in a research center. At the end of Level 1 he calls the player to warn them the center is under attack. If the player goes to the center he meets the Dr. who informs them of the Alien Cell. In Level 5 he reveals he was working with Bahamut. If the player chooses to fight to the end, the Dr. works with a fusion machine to create monsters from enemies faces earlier in the game. eventually, the last one eats him. If you surrender and fight later, (and Deadeye Joe is still alive) you fight him after the death of Joe. Bahamut uses the Dr's science to mutate him into an abomination who fights and dies against the player. If you surrender (and Deadeye Joe is dead) he uses his technology to mutate his own men into monsters. You fight him in the elevator to face Bahamut in his space station. He fights in a 2 legged walker vehicle which looks rather goofy.
in Probotector on sega megadrive, his betrayal edited out and he is removed from all scenes after the research center.