Representative image of a runner from Save the Rhino wearing the Rhino outfit. (Image Credits: Wikimedia Commons)
Green’s intention in writing the book was to use the sales alongside donations to benefit Save the Rhino International, which he revealed on his fundraising page.
The book focuses on a rhino as its central character, and the name Matumaini, which originates from Swahili, translates to “hope”. Green’s conservation efforts have also been translated from track into literary work, having authored a children’s book called Matumaini, The Rhinos’ Hope . The charity focuses on supporting conservation projects across Africa and Asia by engaging with local communities and rangers; it seeks to establish rhino populations and address habitat loss. Taking rhino conservation into the community
The same report noted Green hosted five school visits in April 2025 to educate children about the plight of rhinos, while his effort to hold conversations with the public remains an ongoing project. Green, who donned his moniker as the Rhino Boy, was among the 59,830 athletes who finished the race, and the event, as per estimates from the Olympics, raised an amount above £95 million. Green’s 132-marathon record was confirmed by Guinness World Records, while Save the Rhino International reported that his fundraising had passed £50,000 by April 2026.