Mr. Spock: Miss Uhura, your last sub-space log contained an error in the frequencies column.
Uhura: Mr. Spock, sometimes I think if I hear that word 'frequency' once more, I'll cry.
Mr. Spock: Cry?
Uhura: I was just trying to start a conversation.
Mr. Spock: Well, since it is illogical for a communications officer to resent the word 'frequency'... I have no answer.
Uhura: No, you have an answer. I'm an illogical woman, who's beginning to feel too much a part of that communications console. Why don't you tell me I'm an attractive young lady, or ask me if I've ever been in love? Tell me how your planet Vulcan looks on a lazy evening when the moon is full.
Mr. Spock: Vulcan has no moon, Miss Uhura.
Uhura: I'm not surprised, Mr. Spock.
Captain James T. Kirk: You could learn something from Mr. Spock, Doctor. Stop thinking with your glands.
Captain James T. Kirk: Your wife, Professor, where is she?
Professor Robert Crater: She... was the last of her kind.
Captain James T. Kirk: The last of her kind?
Professor Robert Crater: The last of its kind. Earth history, remember? Like the passenger pigeon, or... the buffalo.
Mr. Spock: The Earth buffalo. What about it?
Professor Robert Crater: Once there were millions of them - prairies black with them. One herd covered three whole states, and when they moved, they were like thunder.
Mr. Spock: And now they're gone. Is that what you mean?
Professor Robert Crater: [nods] Like the creatures here. Once there were millions of them. Now there's one left. Nancy understood.
Mr. Spock: Always in the past tense.
Captain James T. Kirk: Where is your wife? Where is she now?
Professor Robert Crater: Dead. Buried up on a hill. It killed her.
Captain James T. Kirk: When?
Professor Robert Crater: Oh, a year... or was it two?
Mr. Spock: [on why he survived the creature's attack] Fortunately, my ancestors spawned in another ocean than yours did. My blood cells are quite different.
Yeoman Janice Rand: [to one of Sulu's plants] Hello, Beauregard. How are you today, darling?
Sulu: Her name's Gertrude.
Yeoman Janice Rand: No, it's a he plant. A girl can tell.
Sulu: Why do people have to call inanimate objects 'she'? Like, um, "she's a fast ship".
Yeoman Janice Rand: He is not an inanimate object. He's so animate he makes me nervous. In fact, I keep expecting one of these plants of yours to, er, grab me.
Yeoman Janice Rand: Where are you, Sulu?
Sulu: In here, feeding the weepers, Janice.
Yeoman Janice Rand: I've got your tray.
Sulu: May the Great Bird of the Galaxy bless your planet.
Yeoman Janice Rand: [to "Green", who has been following her] Why don't you go chase an asteroid?
Captain James T. Kirk: It's a mystery. And I don't like mysteries. They give me a bellyache, and I got a beauty right now.
Professor Robert Crater: It's the... last one. The buffalo. There is no difference.
Captain James T. Kirk: There's one, Professor. Your creature is killing my people!
Professor Robert Crater: I loved Nancy very much. Few women like my Nancy. She lives in my dreams, she walks and sings in my dreams.
Captain James T. Kirk: And it becomes Nancy for you.
Professor Robert Crater: Not because of tricks, it doesn't trick me. It needs love, as much as it needs salt. When it killed Nancy, I almost destroyed it, but... it isn't just a beast. It is intelligent, and the last of its kind.
Captain James T. Kirk: You bleed too much, Crater. You're too pure and noble. You saving the last of its kind or has this become Crater's private heaven, here on this planet? This thing becomes wife, lover, best friend, wise man, fool, idol, slave. Isn't a bad life to have everyone in the universe at your beck and call, and you win all the arguments.
Dr. McCoy: Lord, forgive me.
[before shooting "Nancy", the creature]
Mr. Spock: Something wrong, Captain?
Captain James T. Kirk: I was thinking about the buffalo, Mr. Spock.
Captain James T. Kirk: Captain's log, stardate 1513.1. Our position, orbiting planet M-113. On board the Enterprise, Mr. Spock, temporarily in command. On the planet, the ruins of an ancient and long-dead civilization. Ship's surgeon McCoy and myself are now beaming down to the planet's surface. Our mission: routine medical examination of archeologist Robert Crater and his wife Nancy. Routine but for the fact that Nancy Crater is that one woman in Dr. McCoy's past.
Captain James T. Kirk: Shall we pick some flowers, Doctor? When a man visits an old girlfriend, she usually expects something like that.
Dr. McCoy: Is that how you get girls to like you - by bribing them?
[Kirk has just dismissed a crewman from the Craters' home]
Captain James T. Kirk: Maybe I'll step outside, too.
Nancy Crater: [referring to McCoy] What? And let Plum examine me all alone?
Captain James T. Kirk: "Plum"?
Dr. McCoy: Plum.
Dr. McCoy: [examining Darnell] Dead, Jim.
[first aired occurrence of his famous line]
Captain James T. Kirk: What's the matter, can't you sleep?
Dr. McCoy: Nope.
Captain James T. Kirk: Try taking one of those red pills you gave me last week. You'll sleep.
Captain James T. Kirk: Remember my instructions, Lieutenant: keep a tight fix on us. If we let out a yell, I want an armed party down there before the echo dies.
Uhura: Message, Captain. Starship base on Corinth IV requesting explanation of our delay here, sir. Space Commander Dominguez says we have supplies he urgently needs.
Captain James T. Kirk: Tell José he'll get his chili peppers when we get there. Tell him they're prime Mexican reds, I hand-picked them myself. But he won't die if he goes a few more days without 'em.
Captain James T. Kirk: Captain's log, additional. Armed and able-bodied crewmen are not attacked and slaughtered this easily. Apparently the killer can immobilize them as it approaches, perhaps with some hypnotic or paralyzing power. The answer lies with Professor Crater.
[Crater has shot at Kirk and Spock]
Captain James T. Kirk: He's not trying to kill us, he's trying to frighten us. And he's doing a pretty good job.
Captain James T. Kirk: There's a body down there. Sturgeon.
Transporter Operator: We'll bring him home, sir.