The Hitchhiker’s Guide to the Galaxy, Douglas Adams
Se: Zaphod’s primary goal in life (if you want to call it a goal) is to make a scene –a very big scene. “Zaphod loved effect: it was what he was best at.” He’s a performer who loves to show off his
skill and talent luck and charm. He’s that guy who gives the party soul, but is also the most likely to forget to think before acting and end up burning down the house (without consuming alcohol). He’s all about action, risk, and never thinks before he acts, and never has a reason for doing anything at all.
Fi: Everyone knows Zaphod is a bit of a narcissist –apparently to the point that he’s capable of seeing the whole expanse of the universe and still not feeling insignificant. His self-obsession comes off as confidence (which is why he’s so good at being president of the galaxy), but really, Zaphod is extremely insecure. He’s very much a drama queen, to say the least. He’s also full of feelings, and frequently experiences two polar opposite feelings at the same time. “Zaphod Beeblebrox paced nervously up and down the cabin, brushing his hands over pieces of gleaming equipment and giggling with excitement.”
Te: Zaphod just doesn’t think. Ever. At all. And he knows it. He’s perfectly aware that he doesn’t always think straight, but seems to be majorly okay with that fact. At the same time, even though he’s pretty much the biggest idiot in the galaxy, he can be rather clever on rare occasions when it’s not expected.
Ni: Zaphod is not a long-term planner, or, really, a planner at all. He usually doesn’t know why he’s doing the things he is, and can’t really understand much of anything. “Trillian had come to suspect that the main reason why he had had such a wild and successful life that he never really understood the significance of anything he did.”
For those folks who have only seen the movie (of which we shall not speak further), Zaphod’s heads do not each have their own personality in the book.