What is the predator-prey relationship between a harpy eagle and a sloth?

No.

Wrong continent. Gorillas are found in Africa, Harpy eagles in South America.

Wrong level of forest. Harpy eagles hunt high in the trees, gorillas, once out of childhood, don't climb much.

Wrong size. Harpy eagles favourite food animals are about sloth-sized. Gorillas quickly become a lot bigger than that.