Large docile Kryptonian animals with horns that have medical healing properties. Rondors are so rare and valuable, that the killing of these beasts is considered an extremely serious crime on Krypton. Rondor horns prove to have the same medicinal effects even when not attached to the living animals themselves and therefore play a key role in the false allegations made against Quex-Ul--resulting in his being imprisoned in the Phantom Zone. After serving time for the crime he didn't commit, Quex-Ul is released from the Phantom Zone by Superman. On Earth, his residual anger leads to the loss of his Kryptonian powers by Gold Kryptonite (S No 157/1, Nov 1962: "The Super-Revenge of the Phantom Zone Prisoners!").
Nam-Ek slaughters Rondors and uses a potion made from the horns to gain healing powers and immortality (S No. 282, Dec 1974: "Loneliest Man in the Universe").