Captain

The Pikmin Captains are the characters of whom the player has control. In the first game, there is only Olimar, an employee of Hocotate Freight who crash-landed on the planet. In Pikmin 2, Louie is added as a second character, also controlled by the player; it is possible to switch between the two playable Captains by pressing the "Y" button.

The captain is followed by Pikmin he has called out of the Onion or plucked, and by lone Pikmin he touches or whistles at. The captain can throw Pikmin for various purposes, or attack monsters himself when no Pikmin are nearby. Puffstools, mature Bulbmin and Antenna Beetles act as naturally occuring enemy captains, in each of the two Pikmin games, stealing the player's Pikmin or scouting with their own, respectively.

Olimar
Captain Olimar, commonly called just Olimar, is the main character of the Pikmin series. He is the Hocotate Freight employee who discovered the Planet of the Pikmin. He is the captain of his personal ship, the S.S. Dolphin, until it is sold to repay some of the debt at the start of Pikmin 2. His family consists of his wife, his son and his daughter, who live on Hocotate and remain there throughout the two games in the series.

Louie
Louie first appears in Pikmin 2 and serves as a partner to Olimar, commanding Pikmin as his sidekick. He is relatively new to the shipping business and has a ravenous appetite. He was raised by his grandmother who made him play with bugs and eat them, from where it is assumed that his great affinity for cooking beasts in Pikmin 2 comes.

After gaining 10,000 Pokos, Louie is replaced by the President. This is because Olimar accidentally leaves him behind on the planet on his return to Hocotate and only realises this, shown in a cutscene, as the ship begins to speed away. The actual reason, however, is never stated. It is unlikely that he jumped out after having taken off on purpose, as he is in a rather shocked and frightened state (noticeable in the credits cutscene, though that may be due to having been left behind).

While he wanders around the Pikmin planet, he comes in contact with a colossal Titan Dweevil. Whatever his intents are with the creature, he is later discovered sitting on top of the great mass, where he remains during the battle with the beast. It is questionable as to whether he is controlling it, as there are few reasons why he should attack the aiding Pikmin and the other captains, who don't seem to show any negative feelings to Louie.

In the end, it becomes apparent that Louie is actually the one responsible for the debt Hocotate Freight suffers, and not a "ravenous space bunny" as he lead the President to believe at the start; it was truly he who ate the load of Golden Pikpik carrots. This is revealed in a cutscene unlocked by getting a pink flower for all 30 of the Challenge Mode levels.

President
The President is the owner of Hocotate Freight, and is a playable character in Pikmin 2. He is called 'Shacho' in the Japanese version, which is Japanese for President, and is often called by that name because he says it when you switch to his character (although it's commonly mistaken as 'Schyaco', 'Syecho', etc.).

He runs into financial trouble after Louie ate the aforementioned Pikpik carrots. The President took out a large loan to reimburse the loss of the carrots, and has no way of repaying the enormous debt. He sold off the only company asset, the S.S. Dolphin, in Olimar's absence, but it only made a small dent in the enormous loan, as 10,100 Pokos are still owed by the time Olimar has returned. This, occurring after the events of Pikmin, shocks Captain Olimar. He is so surprised, in fact, by the news, that he drops a souvenir that he brought back from his "vacation" for his son. The souvenir, a bottle cap, worth 100 Pokos, is collected by the ship, which then evaluates the item as a treasure, reducing the debt to an even 10,000.

The President will be the main source of mail in Pikmin 2 before you erase the debt, his news getting worse as he finds out that the loan agent he actually came to was the All-Devouring Black Hole Loan Sharks, as opposed to Happy Hocotate Savings and Loan, and goes into hiding.

Captain is Down
When a captain loses all his health, he becomes unconscious. In Pikmin 1, the day ends and all Pikmin that aren't in an Onion die. In Pikmin 2, this only occurs if both captains faint; otherwise, the Pikmin that were with the captain become idle, and the captain is moved to the ship, where he lies on the floor until the end of the day.

In Pikmin 1, If Captain Olimar's suit takes too much damage, there will be a cut-scene with him slowly returning to the S.S. Dolphin, in a depressed, perhaps ashamed state. The words "Olimar is down" will then appear onscreen and the day's journal with read as follows:

"I've been careless, sustaining damage beyond my space suit's limits. My crisis transport system saved me, but I lost all of the Pikmin I had with me. I must pay closer mind to my space suit damage meter in the bottom-left corner of the screen. I can press A by the Dolphin to repair my suit."