Dudunsparce is a serpentine Pokémon that looks nearly identical to its pre-evolution, Dunsparce. It has the same yellow body with a blue underside and blue and cream stripes on its back. It sports three "prongs" on its blue chin and its eyes are now partially opened up, revealing its two pupiless white colored scleras. It has a dark blue spiral pattern on the underside of its first body segment, and its tail has a blue "cap" on it.
The most notable change Dudunsparce has compared to its pre-evolution is that its body is longer, having gained segments that are similar to Dunsparce's original body. According to a study, Dudunsparce's number of segments is determined by its genes. Each segment has its own pair of wings and back pattern. Two-Segment Form Dudunsparce have two pairs of body segments, with two blue stripes and a pair of two-feathered wings on the first body segment, and one blue stripe and a pair of one-feathered wings on the second. Some Dudunsparce have the Three-Segment Form instead, which has an additional body segment after the head; this segment has three blue stripes and a pair of three-feathered wings.
Dudunsparce makes its nest, which can reach over six miles (10 km) long, by using its hard tail to bore holes into bedrock deep underground. It drives enemies out of its nest by inhaling air with its long, narrow lungs, and then releasing it in an intense blast. It is also known to be gentle, however, and will carry Pokémon wandering into its nest on its back and guide them outside.
Dudunsparce and its pre-evolved form are the only known Pokémon capable of learning the move Hyper Drill.
- Three-Segment Form Dudunsparce is the tallest Normal-type Pokémon.
- Since Natures were determined via personality value prior to Generation V (which itself is indistinct from encryption constants prior to Generation VI), a Hardy Nature Dunsparce transferred to Generation IX will have a 1/4 chance of evolving into Three-Segment Form Dudunsparce, whereas Dunsparce with other Natures will always evolve into the Two-Segment Form.
- Dudunsparce's cry is composed from Dunsparce's cry, pitched down and with a portion of it repeated multiple times.
Dudunsparce appears to be based on the snake-like Tsuchinoko cryptid of Japan. Its multiple segments may also be inspired by some sphinx moth caterpillars (some mimic snakes, which leads to them being mistaken for Tsuchinoko). Its gourd-shaped body may be a reference to gourd-shaped sake bottles, given that the tsuchinoko was said to have a taste for alcohol. Dudunsparce may also be based on the Nozuchi, which is another snake-like yokai with caterpillar traits but larger and more ferocious than the Tsuchinoko.
The appearance of Dudunsparce's segmentation is similar to the ultrabithorax genetic mutation, observed in the fruit fly. The mutation essentially results in the development of a second thorax directly behind the first, complete with its own extra set of wings.
Dudunsparce may be derived from a partial repetition of Dunsparce, in reference to the former's multi-segmented appearance as well as having an appearance nearly identical to its pre-evolution. It may also be a combination of double or dud (possibly referencing its pre-evolution's almost-useless wings and tendency to remain motionless and inactive, or Dudunsparce's aforementioned relative lack of visual changes from its pre-evolution) and Dunsparce.
Nokokocchi may be derived from a partial repetition of ノコッチ Nokocchi (Dunsparce), for the same reasons mentioned above.