Jonathan is a Seychelles giant tortoise (Aldabrachelys gigantea hololissa), which is a subspecies of the Aldabra giant tortoise.
Jonathan dwells on Saint Helena, a British Overseas Territory in the South Atlantic Ocean.
He's estimated to be 192 years old, making him the world's oldest land mammal. Because of his well-known status, he's even met royalty, including the late Queen Elizabeth II, who visited the island in 1947.
Jonathan landed at St. Helena in 1882 as a present for Sir William Grey-Wilson, who eventually became the island's governor.
Since then, Jonathan has explored and grazed the gardens of Plantation House, the governor's mansion, where he has witnessed 31 governors in office.
Jonathan still lives there, along with three other gigantic tortoises: Emma, David, and Fred.
Jonathan has two Guinness World Records: one as the oldest land animal and the other as the oldest chelonian (which includes turtles, terrapins, and tortoises).
According to Guinness World Records, his age is only an estimate. According to sources, the present Governor of St. Helena gave him an unofficial birth date of December 4, 1832.