The Dweevil Family consists of 6 different enemies from Pikmin 2, one of which is a Boss creature. The genus of this family is Mandarachnia , where "arachnia" most likely refers to their spider-like appearance. All dweevils live underground in Caves, and they have a tendency to pick up Treasures and enemy carcasses and place them on their backs.
The Fiery Dweevil is a species of Dweevil from Pikmin 2. Like other dweevils, it tends to pick up dead enemies and treasures and place them on its back for protection. When threatened, it will expel fiery blasts from between it's legs, killing Pikmin that aren't Red and damaging space suits that do not feature the Scorch Guard. Remember that you can call back burning Pikmin to extinguish them.
The Anode Dweevil is a species of Dweevil from Pikmin 2 that will deliver a deadly shock to any neighboring Pikmin. This species of Dweevil is one of the most dangerous, because unlike Munge, Caustic, and Fiery Dweevils, their discharge attacks will instantly kill all Pikmin (except for Yellow ones, because they are immune to electricity).
The Caustic Dweevil is a species of Dweevil from Pikmin 2 that sprays body fluid onto your Pikmin when it feels threatened, drowning all types but Blue. Like other dweevils, it will sometimes carry objects on its back for safety.
The Munge Dweevil is a species of Dweevil from Pikmin 2 that is able to produce and expel poisonous gases when it feels threatened. This attack does not affect Pilots, but it will definitely cause your Pikmin to start choking, just like with the gas from Gas Pipes.
The Volatile Dweevil is a species of Dweevil found in caves in Pikmin 2. Like most dweevils, they tend to carry objects on their backs; in this case, the dweevil is carrying a Bomb-rock. They often drop from the ceiling and follow you around as the bomb-rocks they carry count down to an explosion. These are very dangerous creatures, because they can instantly kill many Pikmin at once.
The Titan Dweevil is the final boss of Pikmin 2, and is found only on 14th and final sublevel of the Dream Den. It is extremely large and has 4 treasures attached to it, each functioning as a deadly weapon. With these parts in the Titan Dweevil's control, it and can shoot fire, electricity, water, or poison, representing the four main Hazards.