Jackson opted to make Kong a gigantic silverback gorilla without any anthropomorphic features. Eastern gorillas live in stable, cohesive family groups, led by a dominant silverback male. Williams' nickname is "Silverback", named after the male gorilla. Peter sees Amy with a troop of silverback gorillas and bids her goodbye. Their breeding groups consist of one silverback male, three adult females and their offspring. The heaviest silverback recorded was a specimen shot in Ambam, Cameroon, which weighed . Binti Jua has a daughter named Koola with a wild-born silverback called Abe. The tallest silverback recorded was a individual shot in Alimbongo, northern Kivu in May 1938. Ivan was tested if he really was a silverback at the new zoo. The previous silverback, Rikki, had died in 2003. Younger males subordinate to the silverback, known as blackbacks, may serve as backup protection. Without a silverback to protect them, the infants will likely fall victim to infanticide. A group usually consists of one silverback, several females and their offspring. He then embraced his role as silverback and leader of a troop. "Sanctuary" tells the story of what happens to the lady vampires after Silverback is killed.