Shaka Zulu was a Tomas Founder. He wasn't born into the Cahill family, but an English Tomas (Henry Fynn) offered him to be in the family and have a sip of the Tomas serum if he guarded the Clue,Aloe. This Clue was found in The Viper's Nest. Shaka Zulu used the Buffalo Horn strategy to beat his enemies. After the Clue hunt, it is shown in The Black Book of Buried Secrets that Amy's class was studying Shaka Zulu. Shaka Zulu made his appearance in The Viper's Nest, when Tomas professor Robert Bardsley (in disguise) gives Dan a Slimgaard postcard that has suspicious handwriting on it. On the back has a encyclopedia-looking information about Shaka Zulu, Which then they follow Shaka throughout The Viper's Nest to lead Amy and Dan to their next clue.