Spock: A most curious creature, Captain. Its trilling seems to have a tranquilizing effect on the human nervous system. Fortunately, of course... I am immune... to its effect. (begins cuddling and stroking the tribble, then stops himself when the crew look at him and leaves with Kirk)
McCoy: Lieutenant, do you mind if I take one of these down to the lab and see what makes it tick?
Uhura: Well, all right, Doctor, but if you're going to dissect it I don't want to know about it!
McCoy: I won't harm a hair on its head... wherever that is.