Dr. Leonard H. McCoy.
(Voice by DeForest Kelley).
McCoy almost died in 2269 when his life energy was drained by the females of Taurus II. ("The Lorelei Signal"). On stardate 5499.9 Captain Kirk and Mr. Spock were mutated into water-breathers by well meaning Aquans on the planet Argo. Doctor McCoy deciphered the ancient Aquan scrolls and filled n missing information and successfully reversed their mutation. ("The Ambergris Element"). McCoy treated Spock for choriocytosis, a disease that is a mere nuisance to humans but is potentially fatal to Vulcans. ("The Pirates of Orion").
In 2270, McCoy, Sulu and Uhura became trapped in the holographic recreation room when the ship's computer began exhibiting aberrant behavior following the ship's passage through an energy cloud. ("The Practical Joker"). On stardate 5275.6, Dr. McCoy was accused and imprisoned by the Dramans for causing a plague on Dramia II in 2251, but was acquitted after he found a cure to the disease. ("Albatross").
The character of Dr. McCoy appeared in all but two episodes of the animated series, "The Jihad" and "The Slaver Weapon." DeForest Kelley also portrayed Dr. McCoy in the Original Star Trek Series and movies. McCoy's daughter was to have been introduced in an original series episode, entitled "Joanna" by D.C. Fontana, but the script was extensively rewritten and became "The Way to Eden." His daughter's age was never given in dialog, although Bjo Trimble's Star Trek Concordance states that she was 20 years old. McCoy's middle initial was given in Star Trek III: The Search for Spock.