Cave

Caves are underground environments accessed from distinct holes in the ground, which are also used to progress through them, in various areas. When the active leader prepares to delve into a hole, other leaders will follow behind alongside that leader's Pikmin, and Pikmin that are idle, working, or in another leader's squad will return safely to their Onions. The time of day does not pass while inside a cave, although in some fanon games it does, and the sublevels that constitute a cave tend to be randomly generated, although some sublevels in fanon games have static layouts. Each sublevel also has a particular aesthetic theme and may vary in overall difficulty depending on the types and quantities of its contents. The final sublevel always has an escape geyser to exit the cave using, usually after overcoming its final challenge, although earlier sublevels may also have escape geysers. A cave's contents, with very few exceptions, reappear on every visit. Caves present few opportunities to increase the overall Pikmin population, and entering a cave is not possible without Pikmin. In a cave, if all leaders are defeated or all Pikmin die, the research pod cancels the expedition, discarding every item collected in the cave up to that point to accommodate them to bring them to the surface. Planted Pikmin will remain in a sublevel they were buried in and be lost forever if they were not plucked before advancing to the next sublevel or exiting the cave.

=In fanon games=

In Pikmin V
Caves in Pikmin V function very differently than in. Each one has a static layout, evolving on the concept of the, with a series of themed puzzles, often utilizing planning, that stand in the way of progress and treasure collection. Every area except Overlook Hill, and standard underground areas, has exactly one cave in it. The cave is not separate from the area it is located in, meaning time does not stop while inside it, and not all leaders must enter the cave. However, a cave still can not be exited once entered; instead, the head of the Hocotate Hauler will detach to permanently collect any treasures within. The Hauler only has one intake, so entering a cave will prevent treasures from being collected at the landing site; the Pikmin will act as if their path is blocked once they reach the point where their treasure should be sucked up. When the S.S. Drake is recovered, this ceases to be an issue, as it takes over that duty while the Hauler Head is away.

Cave entry is initiated with a prompt that displays the cave's name, the number of treasures within and how many are collected, and which types of Pikmin are recommended for use. This happens once per day; the prompt is also viewable any time after the cave's discovery through overhead mode. Once inside of the cave, interacting with the Hauler Head will prompt escaping with only the active squad. The Head will return to the cave if there is still a leader inside, but stray Pikmin can be left behind. Unlike the Research Pod, the Hauler Head will refuse to store carcasses long-term: exiting the cave with anyone will cause it to spit out all collected spoils at the cave's entrance despite taking the group to the landing site with it, and it will destroy them if an exit is not made by the end of the day. The Head also serves as a safe zone separate from its body when sunset arrives.

Lastly, at the end of each cave is a Pikmin 2-style miniboss that contains an upgrade-providing treasure. The only exception is the required story boss in the Deep Palace.

In Pikmin: Redemption
The Nightmare Den is the only nightmare cave that didn't get cut during beta testing for the game to be able to get an E10+ rating. It is comparable to the from.

In Pikmin: Sister Incinerator
In Pikmin: Sinister Incinerator, Dark caves are similar to ordinary caves, but are unique from other types of caves in that they each contain an abundance of dark fog at its entrance and a single dark spore on its final sublevel. Upon defeat, a boss holding a Dark Spore will spit it up, and it can then be collected as a treasure. A Dark Spore will lose the corruptive influence it had upon being absorbed by the Research Pod. There is one dark cave in each area, save for the Portal, which has only one dungeon. Dark caves are generally the farthest from the landing site and take the longest to reach. They are the deepest in their respective area.

In Pikmin: Wide World
Caves make a return from  and appear in Pikmin: Wide World, serving the same purpose as they did in the past. Caves are underground areas that can be accessed from various holes in the ground of certain regions of aboveground areas, and generally contain just as many treasures and fruits as they do enemies and hazards. Plants are also often found in caves, matching the theme of the sublevel they are on. Various objects and enemies may also fall from the ceilings of caves. A cave variant known as dens can be found and consist of one to two tranquil sublevels. To create a more realistic atmosphere, all sublevel themes feature occasional patches of dirt, sand, or snow, depending on the cave's location. The primary sources of light in caves is usually a leader's beacon, although some enemies and plants may also produce light. The hole to the next sublevel cannot be entered until the area around it and the path to it from the Lander Pod are secured; dangerous enemies close to it or near the path to it must be defeated and most nearby hazards must be neutralized. All caves can be exited using an escape geyser that is present on the bottommost sublevel, although escape geysers may also be found on tranquil sublevels. Some escape geysers must be activated by having Pikmin attack them before they may be used. The contents of a cave do not reappear for seven days after collection.

Every cave sublevel in Pikmin: Wide World utilizes one of several themes, some returning from Pikmin 2. Although themes are usually consistent for the entirety of a cave, some can vary. Some themes can also be mixed. They usually match the environment in which the cave's entrance was discovered. The following is a list of cave themes appearing in Pikmin: Wide World, organized by alphabetical order:
 * Concrete: Features concrete floors and walls, with patches of dirt, sand, or snow between slabs of concrete. Enemies cannot burrow into the concrete. Pipes, rebar, and large chunks of concrete serve as indestructible obstacles.
 * Dirt: A very basic and simple cave theme that possesses dirt floors and walls. Rocks and pieces of wood are occasionally present to make up portions of the floors and walls, and also to serve indestructible obstacles.
 * Metal: A special theme which has two subtypes that can be used together. The first, which returns from Pikmin 2, is named metal walkways: it has low walls, which makes it possible to throw Pikmin to their demise. The second is entirely new and is named metal interior: it resembles a typical cave in that it has high walls. Both subtypes are composed entirely of metal and feature patches and piles of colored sand. Mechanical enemies are common in this cave theme, and much like with the stone theme, enemies cannot burrow into the hard metal.
 * Nature: The spiritual successor the Pikmin 2's garden theme. Many plants and fungi cover the sublevel floor. Mud is frequent in this theme.
 * Sand: Features sand and sandstone, which comprises the floor and walls, respectively. Water is a frequent hazard in this theme.
 * Snow: Very similar to the dirt theme, but has snow covering the floor and walls. This cave theme is only ever encountered in Frigid Tundra, and only on the first few sublevels of a cave before it transitions into the soil theme. Rocks are sometimes present in these caves to break up the monotony of the dirt.
 * Stone: Has smooth stone comprised much of the sublevel's surfaces, but depending on where the sublevel's cave is located, can also contain trace amounts of dirt, sand, or snow. Enemies are unable to burrow into the hard rock. Stalagmites, stalactites, and columns of stone serve as indestructible obstacles.
 * Tiles: Small colored tiles cover nearly the whole sublevel. Water is a frequent hazard in this theme. Enemies cannot burrow into the tiles. Piles of dirt, sand, or snow may also appear and serve much the same purpose as the metal theme's colored sand.
 * Wood: Lumber is frequent in the sublevel and some pieces may serve as indestructible obstacles. Wood makes up much of the sublevel's floors and walls. Enemies may burrow into wood even though it is a hard surface type.

Sublevels may also have one or more modifiers that drastically change how they are navigated:
 * Flooded: Water covers a majority of the sublevel and very little dry land is available as a result. A clog is usually present, either blocking the hole to the next sublevel or located elsewhere. Destroying it will drain most of the water from the current sublevel. The clog does not need to be removed if enough of the land around the hole to the next sublevel is dry.
 * Dark: Visibility is abnormally low, and light sources are less effective than normal.

In addition to having themes they are styled around, four different sublevel classifications exist in Pikmin: Wide World that are based off of the number and type of enemies it houses:
 * Tranquil sublevels, also known as rest sublevels in larger caves, are sublevels that are usually devoid of enemies and hazards. Non-Pikmin-endangering obstacles may also be present. If any enemies are present, they are either harmless or easy to kill. Tranquil sublevels contain few treasures and fruits, but are worth exploring regardless as they may contain eggs, Candypop Buds, or other useful items. Tranquil sublevels compose most of the single-sublevel dens found throughout the game.
 * Perilous sublevels contain several dangers, of which are posed by enemies, hazards, and some obstacles, and have roughly equal amounts of each. Perilous sublevels are as rewarding as they are dangerous, also housing several treasures and fruits.
 * Infested sublevels contain massive quantities of enemies and may additionally be home to a few bosses. The number of enemies present in this sublevel type strongly outweighs the number of obstacles and fruits present, if there are any present in the sublevel. Infested sublevels are the most rewarding treasure-wise.
 * Boss sublevels are, as the name would imply, where the cave's boss lurks. Although some hazards and obstacles may be present on boss sublevels, they are generally devoid of enemies. Sometimes this type of sublevel may contain very few enemies that are scattered around the area.