Hergé's Arumbaya fetish was based on the design of a genuine Peruvian statue in Brussels' Royal Museums of Art and History; a pre-Columbian Chimu statue, it was made of wood and dated to between 1200 and 1438 CE. Whereas Hergé had access to speakers of Mandarin when creating "The Blue Lotus", he had no access to speakers of indigenous Amerindian languages, and as such, the Arumbaya language that he developed was entirely fictitious. He based its structure largely on the Brusseleir dialect spoken in the Marolles area of Brussels, mixed with Spanish endings and constructions. In developing the Arumbaya's rivals, the Bibaros, he was influenced by anthropological accounts of head shrinking among the Jibaros tribes; when Leslie Lonsdale-Cooper and Michael Turner translated the book into English, they renamed the Bibaros as the Rumbabas, a pun on the rum baba pudding. The explorer Ridgewell, found living among the Arumbayas is based upon the British explorer Colonel Percy Harrison Fawcett, who mysteriously disappeared into the Amazon jungle in 1925.