It is not known to evolve into or from any other Pokémon.
Dunsparce is a serpentine Pokémon with a primarily yellow body, blue underside, and blue-and-cream-striped back. Its head is round with a wide mouth extending under its jowls and curving up toward the middle of its face. Its chin is blue with two rounded prongs. Its eyes—round and rimmed with blue—are kept closed, revealing its cream-colored eyelids. On Dunsparce's upper back are two small, white, bird-like wings split into two sections each. Its body ends in a striped, drill-like tail.
Though Dunsparce can float slightly with its wings, it avoids detection and flees when spotted by burrowing into the ground with its tail. It lives immobile in caves and beneath the earth, where it makes maze-like nests. They get along with Diglett and share tunnels with each other.
Multiple Dunsparce debuted in The Dunsparce Deception, where an entire town was full of children owning the Land Snake Pokémon. Bucky was the only child without a Dunsparce and asked Ash and his friends for assistance. In the end, he was able to catch himself one.
Dunsparce is based on the mythical Tsuchinoko, a serpentine cryptid of Japan. Similar to Bigfoot or the Chupacabra, sightings and reports appear in Japanese media; however, hard evidence is always lacking. Tsuchinoko are 30 cm to 80 cm long, with a large head and poisonous fangs. Its body is thicker than its head and tail. The noises it makes resemble squeaks, chirps, and snores. Unlike real snakes, which slither from side to side, a Tsuchinoko wiggles ahead in a straight line. The Tsuchinoko curls its body to leap through the air.
Moreover, the fact that Dunsparce, a snakelike creature, has wings also brings to mind the motif of the Feathered Serpent, a prominent deity or supernatural being in many Mesoamerican religions. In addition, Dunsparce shares some traits with bumblebees, including their stripes, tiny wings, stinger-like tail, and the fact that they burrow into the ground. This may be a visual pun inspired by the name "bachi hebi" (literally "bee snake"), which the Tsuchinoko is also known by. Dunsparce also may draw some inspiration from amphisbaenians, small, blind reptiles that lack limbs and are adept burrowers, much like Dunsparce.
Alternatively, in addition to being a pun on "bachi hebi", Dunsparce may draw inspiration from sphinx moth caterpillars, which are sometimes mistaken for the Tsuchinoko. This is mostly apparent from its ring-circled eyes that resemble the eyespots of some species, combined with its horn-like tail.
Dunsparce may be a combination of dun (grayish yellow or gloomy), dunce, and sparse (referring to its rarity).
Nokocchi is an anagram of ツチノコ Tsuchinoko, a fabled snake-like creature.