Cecil Clayton, more commonly known simply as Clayton, was the main antagonist of Tarzan. He was Tarzan's arch-nemesis.
Biography
Tarzan
Clayton first started out as a rather haughty and aggressive guide who was clearly more interested in hunting animals than researching them, much to the displeasure of Jane and her father - who were searching for gorillas for research rather than for profit. Despite his behavior, Clayton didn't show signs of being a true villain at that point, though he was always slightly antagonistic. However, his antagonism worsened when the group came across Tarzan. Clayton figured that this "missing link" could be his ticket to finding the gorillas and he tried to get Tarzan to aid him.
However, Clayton was neither patient nor particularly nice, thinking of Tarzan as inferior and somewhat stupid (without knowing that Tarzan is actually both stronger and smarter than he is). Eventually, Tarzan did lead the group to the gorillas, but more out of his growing love for Jane and the way she and her father had treated him (with respect rather than insults). Clayton came along under the false promise that the gorillas wouldn't be harmed.
Once he learned of the gorillas' home, Clayton's true nature quickly surfaced as he had Jane, her father, and Tarzan captured and imprisoned - it was then Clayton revealed what he truly was: A poacher. Soon, Clayton and his henchmen begin to cause havoc in the jungle, snatching gorillas and putting them in cages, presumably to be either sold or killed.
However, Tarzan manages to escape and fights Clayton to save his family. During this conflict, Clayton shoots Kerchak later, the tragedy of the moment is made worse as Kerchak finally accepts Tarzan as his son, only to die. Angered, Tarzan renews his attack on Clayton and gets the upper-hand, holding the rifle to Clayton. The poacher mocks Tarzan and tells him to shoot him and be a "man". But Tarzan regains his senses and smashes the rifle against a tree, stating bitterly to Clayton that he was "not a man like you". Clayton is unmoved and proceeds to attack Tarzan with his machete, but he's too quick and agile and uses vines to try and restrain Clayton. But this only serves to Villainous Breakdown, drive Clayton into a frenzy and he slashes at the vine, unaware of one of them tightening around his neck. Tarzan realizes what was happening and warned Clayton to stop, but the mad hunter wouldn't listen and ultimately cut the vine he was holding, making him plunge down as the remaining vine wrapped around his neck and effectively hanged him, snapping his neck instantly, a flash of lightning revealing his hanged corpse.
In The Legend of Tarzan
Clayton doesn't physically appear in the series, but he is mentioned once.
During one episode, Clayton's sister comes after Tarzan, seeking vengeance for what she saw as her brother's cold-blooded murder. However, when Tarzan managed at great risk to save her from a fate similar to Clayton's, she came to realize that the man who did this for her couldn't be a savage killer and left the jungle.
Kingdom Hearts
Clayton finds Donald and Goofy and brings them back to the tent where they are reunited with Sora. Clayton meets Tarzan and asks for the whereabouts of the gorillas, and Tarzan obeys and reveals the location. Clayton soon finds Terk the gorilla and tries to shoot her, but is stopped by Donald. He says he tried to shoot a snake attacking Terk, but they don't believe him and he is reprimanded. Furious, his anger attracts the Heartless, who he decides to use to kill off the gorillas. He kidnaps Jane and Terk and hides them in the forest and then brings the Heartless to the gorilla location. As the Heartless are about to attack, Tarzan arrives, joined by Sora, Donald and Goofy, and a battle erupts. Clayton takes aim at his enemies and uses his gun as a club, but is defeated. Clayton wasn't done yet, and called upon the Stealth Sneak to help fight his enemies. Now a bigger threat than before, Clayton battled once more, but was knocked down by Clayton. As he takes aim at Sora, the Stealth Sneak is subdued and falls on him, crushing his body and killing him.
Against Sora's Team
After being recruited by Maleficent, Clayton is able to summon magical guns and use them against Sora for revenge.