Probotector

Probotector is a series of robotic counterparts in Contra series. When Konami released the NES version of the original Contra in the PAL region (Europe and Australia) they modified the game by replacing the original main characters and most of the human enemies with robotic counterparts, retitling the game Probotector (a portmanteau of "Robot" and "Protector"). The title referred to the two robotic soldiers modeled after Briareos Hecatonchires,   RD-008  and RC-011, who replaced Bill and Lance in this version. This was presumably done due to the German Federal Agency BPjM, which banned the sales of  media deemed too violent for children, including "content which glorifies war", thus necessitating the change to robotic characters.

In Contra 4, Probotector appears as a secret character, and recieved something of a canon update; Probotector units are armed recon robots specifically used in areas normally too dangerous or threatening for humans to enter, an open reference to their appearance as the protagonists of the early European Contra games. Much as was the case for Scorpion and Mad Dog in Contra 4, Probotectors canonically served alongside Bill Rizer and Lance Bean during the first Galuga Island conflict.

RD-008 Is the first player in Probotector, is gray and also appears as an extra character in Contra 4 called probotector. And RC-011 Is the second player in Probotector, is blue and appears as an extra palette for RD-008 in Contra 4.