Fleshkiller started in 2016 in Sweden as a side project of Ole Børud of the progressive metal band, Extol and Peter Dalbakk of the band Vardøger. Børud and Dalbakk were former bandmates of the band Schaliach, a death metal band they formed together. The two hired drummer Andreas Skorpe Sjøen from the band Umpfel. The band added Ole Vistnes as the band's bass player, of the bands Shining and Tristania. Dalbakk would later quit the band due to spending more time with his family. The band would replace Dalbakk with Elisha Mullins, vocalist of The Burial and former guitarist of .