Final Fantasy IV/Developer's Office

The Developer's Office is a secret area available in all versions except the North American SNES release, accessed by walking east through a hidden passage in the Dwarven Castle Pub. It contains all of the developers of Final Fantasy IV for you to talk to, with random encounters for some of them as well, each with their own script and gag. The only item here is the Lustful Lali-Ho located in the bookshelf of the basement, which is a joke item that has no effect besides a funny scene when used.

Tetsuya Takahashi
Tetsuya will keep saying "You wanna die?" until the battle ends, but this does nothing. Her defenses are high enough that your attacks won't do any damage to her. The easiest way to kill her is to cast Poison, then cast Toad, and then attack her.

Akihiko Matsui
Akihiko will start the battle bragging about his stats, cast Libra on a random party member, cast Libra on himself, and then run away in shame.

Kiyoshi Yoshii
Kiyoshi won't attack you, and will instead cast Sleep on himself and then run away after a series of messages.

Hiroyuki Ito
Same as Kiyoshi, Hiroyuki won't attack, and will cast Sleep on himself.

Hiromi Nakada
If attacked, Hiromi will say "Clumsy!" and counter with Slap. She will eventually retreat once her manager calls her.

Kazuhiko Aoki
Kazuhiko will retreat the first turn he gets. If you get a pre-emptive strike, you can cast Stop on him and potentially kill him.

Katsuhisa Higuchi
Attacking him for 1HP of damage will cause him to use Detonate and deal 1HP of damage to a party member, otherwise he will just die with a single hit.