HMS Panther was a planned Leopard-classfrigate, but she was launched instead for the Indian Navy as Brahmaputra in 1957. She was deleted from the Indian Navy Lists in 1985.
HMS Panther was a planned Salisbury-class frigate, ordered in 1956 but her name was changed to HMS Gloucester, before being eventually cancelled. Gloucester was subsequently reordered as a Leander-class frigate. Note, however, that no Leander-class frigate named Gloucester ever served in the Royal Navy. The name Gloucester was re-used in 1982 for a Type 42 destroyer.