Roy was born Uwe Ludwig Horn on October 3, 1944, in Nordenham, in the midst of bomb attacks, to Johanna Horn. His father died in World War II, and his mother married a construction worker after the war ended. She later began work in a factory. Horn had three brothers: Manfred, Alfred, and Werner. Horn became interested in animals at a very young age and cared for his childhood dog named Hexe (witch). Horn's mother's friend's husband Emil was the founder of the Bremen Zoo, which gave Horn access to exotic animals from the age of 10. Horn left school at age 13. He worked as a waiter on the cruise ship "Bremen", where he met Fischbacher and launched his performance career.