Skull-Head
Skull-Head was the male alpha of Skull-Head's troop, the largest single troop of monkeys in Monkey Hill and one of the largest monkey troops in the world (with over 300 members), for over 20 years. As a result, he is well-known to humans, even appearing on the cover of a government brochure for Monkey Hill.
Skull-Head, who is now elderly, was deposed as alpha in late 2021. However, he was able to remain in the troop, and will likely live out the rest of his days as a high-ranking male in the troop that bears his name. He is still well-respected in the troop, with many high-ranking members still offering fear grimaces and presenting their bottoms (both signals of submission) whenever he passes by.
Despite his name and ferocious look, Skull-Head is quite amiable and approachable, and deals well with humans. He treats monkey babies with gentleness and care.