Jake Muller (ジェイク・ミューラー Jeiku Myūrā?) was a mercenary raised in Eastern Europe. The son of bioweapons developer Dr. Albert Wesker, he was dragged into a conspiracy to launch major terrorist attacks with the C-Virus.

Muller was born in a single-parent household in Edonia. Previously an émigré to the United States, Muller's mother returned to her home country pregnant, having broken up with her partner Dr. Albert Wesker, then an Umbrella intelligence agent, who was unaware of his son.[1] As she still loved him, Muller was raised to respect his father, who he privately considered a "dead-beat". When his mother fell ill sometime in the early 2000s, they fell into arrears.[3] Seeking a means to support her, Muller entered work as a mercenary, possibly starting with the Edonian Liberation Army, in 2007.[1][3] Unskilled, he was quickly drilled by an instructor to taught him not only to fight, but to trust and support his unit.

Travelling across the world, by 2009 Muller was operating in South America with the same unit. It was wiped out in an ambush, Muller surviving by fighting hand-to-hand with one of the attackers, himself armed with a knife.[4] When it was discovered the ambush occurred because their trainer sold them out, Muller lost his faith and trust in others, and for the next three years built up a reputation in not caring for the ideologies of those he fought for, only caring about the money.[4] Working for various paramilitaries including those in the Middle East, Muller built up a reputation for his lack of conviction.