Rudolph is a character from the game DOOM 3. It is a small Sentry Bot (real name) that has the objective of guiding Pewdie to a certain elevator of the UAC base.
Rudolph first appeared in the first episode of the playthorugh.
In the third episode of the playthrough, Pewdie randomly calls one of the possessed zombie-like men "Rudolph," but later coments that it was a mistake, and that Rudolph is indeed the small robot.
In the following episode, Rudolph is seen wandering around some corridors clearing the path of enemies for Pewdie. However, when Pewdie tried to help and kill some enemies, he got caught in Rudolph's line of fire and was accidentally shot several times.Rudolph has appeared twice over the course of Doom 3 to assist Pewdie in his fight against the demons. Despite Rudolph's efficiency in clearing Pewdie's path, the latter still insists on rushing ahead of Rudolph and doing the work himself.
Whenever Rudolph feels his work assisting Pewdie is completed for the moment, he likes to find small yellow painted squares on the floor (see picture) to lay down and sleep until he is needed again.