Cryptid Hunters, by Roland Smith

Cryptid Hunters is about two kids named Grace and Marty who were twins and their parents disappear in a helicopter crash. After that, they were sent to their "uncle" Wolf. Wolf hunts cryptids and works and owns a company and an island. In case you don't know, cryptids are animals never proved to have existed or who are believed to be extinct. Grace and Marty have lots of adventures including falling out of a jet 18,000 ft. above ground, surviving the Congo, experiencing a real explosion, and collecting fresh eggs from a sauropod. If you like laughing yourself to death, "fantasy", and mystery, read this book.