Hermann Slikk (24 January 1910 - 24 May 2015) is Leopold, Leonard, and Leonidas Slikk's great grandpa, Harold & Gerald Slikk's grandfather, and he is also the father of Barry Slikk who appeared in Atarster's AGK Series. In Episode 50: AGK's Great-Grandfather (Episode 88 in AGKandRockman2001's AGK series), Hermann kidnaps Harold and he put him on the top of the building. Meanwhile, at Leopold's house, the boys watched the news about Hermann kidnapping their father, and they went to the city to stop him. Leopold went to the top of the building, and he decided to fight with Hermann Slikk, which he agreed to. After the fight, the helicopters (they are called from Leonard Slikk) are flying to the place where Hermann is at, and they start shooting. Hermann used his sledgehammer to hit one of the helicopters, and one of them is destroyed. Hermann falls down from the building, and Leopold saved Harold, and he thanked him for saving his life.