Senior Corporal Jakub Kowalski (Callsign: Fusil) hails from Gdańsk, Poland. Jakub is the eldest of seven siblings, having developed a tough but fair temperament through raising his brothers and two sisters. Jakub became interested in the more technical side of things by helping with his father's construction business, leading to him studying engineering at university. Shortly after his studies, he enlisted in the Polish Land Forces.

Demonstrating proficiency in his trade, he would transfer to the Special Troops Command, joining the elite Jednostka Wojskowa Komandosów. After several years with the JWK, Jakub would be recruited to join S.O.F. 303 as the unit's demolition expert. In his role, Fusil is often called upon to breach or carry extra ammunition for the squad. He also often carries a M79 grenade launcher, as well as his shotgun. Fusil is fluent in Polish, German and English. He is also an International Master in correspondence chess.