Since the MSX days modifying top games to become even more challenging and fun, Freddy Hajas it's for sure one of the first modders around, doing this many years before the terms "mod", "modder" or "modtools" even exist. Most know works: - Call of Duty Frontlines Series . Call of Duty 4 Modern Warfare . Call of Duty 4 Galactic Warfare . Call of Duty World at War . Call of Duty Modern Warfare 2 . Call of Duty Black Ops - HER Series . Medal of Honor Airborne . Battlefield 2 . Battlefield 2142 . Battlefield 3 . Star Wars Battlefront II - Quake 2 Evolved Blood Culture - SWOS Brasil Many gameplay features and gametypes created here was introduced in many blockbuster games around the world, such as: . Call of Duty World at War . Call of Duty Modern Warfare 2 . Call of Duty Modern Warfare 3 . Call of Duty Black Ops . Call of Duty Black Ops II . Call of Duty Black Ops III . Call of Duty Black Ops IIII . Call of Duty Ghosts . Call of Duty Advanced Warfare . Call of Duty Infinite Warfare . Call of Duty: WWII . Battlefield: Bad Company 2 . Battlefield 3 . Battlefield 4 . Battlefield V . Battlefield 1 . Star Wars Battlefront 2015 . Almost all Coop/Zombies games since 2008 uses the Help Mode system from Frontlines, first used in the Call of Duty Nazi Zombies then spread around the world.