Bulborbs (チャッピー?, lit.: "Chappy") are the most common, standard, and well-known enemies in the Pikmin games. They were originally called Spotty Bulborbs in Pikmin, and then Red Bulborbs in Pikmin 2, before being simply called Bulborbs in Pikmin 3 and later games. Due to their unparalleled prominence in the series as enemies, they are often just as much a staple for the games as the Pikmin and Olimar, getting significant exposure via marketing and spin-off media. Bulborbs are nocturnal creatures, and sleep in open locations during the day. In the main series of games, this exposes them to being attacked by Pikmin, as they won't wake up until they are attacked. However, Dwarf Bulborbs in Pikmin will let out a screech when agitated, awakening any nearby Bulborbs. Once awake, they become aggressive, and will run towards nearby Pikmin and lunge at them to try and eat them. If it manages to catch any Pikmin, it will stand up and eat them; otherwise it will try again. If there are a lot of Pikmin attacking it at once, it will shake them off and then start trying to eat again. If their eyestalks are attacked, they will panic and break off whatever they are doing to shake away their assailants. In Hey! Pikmin, a Bulborb takes on the role of the boss of the Brilliant Garden. It is larger and moves slower, but is also more aggressive, and is no longer nocturnal. When defeated, it drops the Flashy Monument. Bulborbs are among the creatures with the most diverse physiology in the Pikmin series. They possess traits similar to those of amphibians, reptiles, and mammals. They have large bulbous eyes set in stalks, as opposed to the compound eyes of most insects. These eyes are purple in Pikmin and Pikmin 2, but appear more anthropomorphic in Pikmin 3, with large black pupils and blue irises. Olimar mentions the Bulborbs having a set of mandibles. Mandibles are a pair of appendages near an insect's mouth, used for grinding and chewing food. The so-called mandibles Olimar mentions in his notes look nothing like normal mandibles and are instead most likely saber-teeth, used for breaking exoskeletons of prey insects and digging through the soil for roots. (That being said, "mandible" is also a technical term for the jaws, in which case its use is unremarkable.) Their diet is, however, quite the mystery, as they are equipped with eating both animal and vegetable life, but they are known to fully ignore Spectralids. It seems that the juvenile Bulborb is the favored host of the parasitic Pikmin known as Bulbmin. This type of Pikmin appears to control its host, causing the animal to behave less like a Bulborb and much more like a Pikmin, following a leader (which is naturally an older Bulbmin) and hunting in packs. Bulborbs are not observed at the two stages of development displayed by Bulbmin anywhere else in-game (unlike the Spotty Bulbear), so it is unknown whether Bulbmin are a common stage in Bulborb initial development or not, as symbiotic cooperation from the parasite would give this slightly weaker form of Grub-dog an advantage in the subterranean environment that all stages of the Bulborb species are found in.
