Leafling

Leafling is the name given to characters that cannot be identified because their heads are entirely covered by leaves. Their ID badges are unreadable due to corrupted biometric data, listing their name as "???" or "Error" and their home planet as PNF-404. Olimar as a leafling can be seen kidnapping a castaway, dragging it into an Onion, and making it pop out as a leafling. He justifies this by saying that those that don't embrace dandori cannot survive in the planet, but they thrive instead if they have the leaves. This is how leaflings are made, and Dingo speculates that Yonny, the Rescue Corps doctor, might be able to help bring them back to normal.

Leafling castaways can be rescued from Dandori Challenges and Dandori Battles, both of which are issued by characters that are themselves leaflings. In this state, leafling characters are unable to speak in normal sentences, instead using simple words and small sentences at a time, and are obsessed with dandori. They will hand over the leafling castaways they have, or fall unconscious so they can be rescued themselves, if they witness a good display of dandori in their challenges or battles. Glow sap from a Lumiknoll can be made into medicine by Yonny that dissolves the leaves, reverting the leaflings to their normal state. According to dialogue from cured characters, they remember their time as leaflings but retain the personalities they had before becoming obsessed with dandori.

Following his curing, Olimar believes that leaflings may have had Pikmin DNA incorporated into their bodies after being taken into an Onion, triggering their physical and psychological changes and causing them to rapidly sicken if they try to leave PNF-404. Although he does not know what purpose this "Pikmin-ification' might have, he speculates that the Pikmin may be trying to create a permanent leader for themselves.

Appearance
Leaflings wear regular gray spacesuits, but without a helmet, and their head is covered with leaves, almost like a head full of hair. Only their noses (if any) and eyes are visible. Different characters have different colored foliage. The color of the leaves on a leafling's head matches the hair color of the castaway once they're cured.

Atop their head is a stem with a leaf, much like that of a Pikmin. Fainted leaflings will also have a glow matching their leaves' color, similar to when a Pikmin is idle.

Dandori cave leaflings
Leaflings can be found inside of both Dandori Challenge and Dandori Battle caves. They often speak in broken English, always centered around the concept of dandori.

In Dandori Challenge caves, they act as hosts and comment on the player's dandori skills as they progress. The first of these, seen in the Dandori Day Care explains that the caves serve as a test designed to develop one's dandori skills. After completing the challenge, the leaflings faint from how quickly the player worked after giving them 30 raw material, and can be brought back to the surface and carried to the S.S. Beagle. If failed, the leafling will only give 10 and also will insult the player’s Dandori skills

In Dandori Battle caves, they act as prizes. The red leafling carries them from the surface and converts them into leaflings using their Onion. The player can rescue them only if they can defeat the red leafling in a Dandori Battle. If they are defeated, they surrender the leafling, who can be taken back to the surface and carried to the S.S. Beagle. In Hot Sandy Duel and Final Battle, the player instead saves Yorke and Nelle, who (thanks to their consumption of glow sap prior) are immune to becoming leaflings.

Castaway leaflings
Later in the game, some castaways found in caves will instead be leaflings. They function identically to a standard castaway, though they must be cured with glow sap like prior leaflings. The order in which players cure leaflings will remain unchanged by this different method of obtaining them. The location for these leaflings are as follows:


 * Doppelgänger's Den sublevel 4: inside a group of jars, which are behind a numbered gate opened by defeating a Gildemander.
 * Frozen Inferno sublevel 4: behind a number gate opened by defeating a Snowfake Fluttertail.
 * Plunder Palace sublevel 5: being dragged or buried by a Giant Breadbug.
 * Ultimate Testing Range sublevel 3: stuck to an Arachnode's web.
 * Subterranean Swarm sublevel 3: stuck under some sticky mold.

Leafling Olimar
A red leafling that has Captain Olimar's suit, nose, and voice. Unlike the prior leaflings, he uses correct grammar, though still obsesses over the idea of dandori. He is usually seen accompanied (and later guarded) by Moss. Both are seen stealing castaways and turning them into leaflings via their Onion, as they believe that those who are not leaflings cannot survive this planet. The mysterious duo challenges the player to rounds of Dandori Battles, returning the castaways they steal only when the player wins. They are first battled in Trial Run, Battle in a Box, and Dandori Castle.

In Hero's Hideaway, he is revealed to be Olimar himself through various late entries in his voyage log. After opening the safe he is inside, he challenges the player to one more battle, Leafy Showdown. Once he is defeated, he has no castaway to give and instead falls unconscious to be rescued as Moss runs away. Once he is rescued and cured, he reverts back to his usual non-leafling self.

Louie later finds the abandoned Moss and takes over Olimar's role as a Dandori Battle opponent.

Sage Leaf
The Sage Leaf is a white leafling found in a hidden cave in the Rescue Command Post, which is only revealed after completing Olimar's Shipwreck Tale. They oversee the Trial of the Sage Leaf, a series of ten complex Dandori Challenges with varied objectives. Like the red leafling (Olimar), they speak normally.

Though they refuse to be rescued or cured, they will reward the player with the White Onion and Purple Onion upon completing their fifth and tenth trials respectively. Recompleting the fifth and tenth trials will reward the player 10 White Pikmin and Purple Pikmin respectively. It remains unknown who this Sage Leaf was before they became a leafling (the Sage Leaf has long since forgotten their former identity and says that they have no desire to reclaim it), but given their old age, it would seem they have been one for a long time.

Space dogs
The space dog Moss is affected by a similar condition to humanoid leaflings: she has a leaf on the tip of her tail, cannot leave PNF-404 without falling seriously ill and shares some of her DNA with the Pikmin. Her backstory is unknown, but Olimar believes she has been this way since birth.

After Bernard has been cured, the Rescue Pup Oatchi grows a leaf on his tail similar to that of Moss. This becomes a problem when the Rescue Corps has rescued Olimar but cannot leave PNF-404 without Oatchi suffering the same symptoms that other leaflings would. After acquiring the Gift of Friendship, Yonny extracts some of the Ancient Sirehound's cells from the collar and makes a special cure that reverts Oatchi to normal.

Rescue order
Like castaways, leaflings are rescued and cured in a particular order no matter where they are found. It should be noted that leaflings are cured in the same order they are rescued. While the order won't change, one thing that does change based on the order rescued is hair color, as each cured castaway's hair will match the color of their former leafs.

Dandori Battle leaflings
The only exception to the order of leaflings are those rescued from Dandori Battle caves, who have their own order. When being cured, they take precedence over normal leaflings found as castaways or for completing Dandori Challenge caves. All four must be rescued to progress the game's story. As stated above, their role is filled by Yorke and Nelle in later Dandori Battle caves, who do not need to be cured.

Leafling body type
After the player has rescued Puddle and completed the "Leafling Meet and Greet" side mission, Puddle can customize the player character's appearance to resemble a leafling.

Trivia

 * Many of the leaflings share colors with Pikmin types: red, green, white, blue, purple, and pink. The only color that isn't a Pikmin type is orange, although it's arguable that it's yellow, or amber (the color between orange and yellow).
 * The concept of Olimar being turned into a Pikmin-like creature was introduced in the "bad" ending of the first Pikmin, in which the Pikmin carry an unconscious Olimar to the Red Onion, which absorbs him and releases an Olimar head-shaped Pikmin seed. The scene of Olimar becoming a leafling in Olimar's Shipwreck Tale mirrors this sequence.