Dewpider resembles a spider with a water bubble over its head. Its head and most of its abdomen are dark gray, while its thorax and six legs are light green. All of its legs are thin with a knobby joint in the middle, and three of its legs are typically used to anchor the bubble on its head. The green on its thorax extends onto its abdomen in three triangular markings. There are also several triangular flaps that extend upward and attach to the bubble over its head. The head itself has large light blue eyes with darker pupils and sclerae, two blue bumps on top, and light green mouth similar to a spinneret. There is an actual spinneret on the tip of its abdomen, which the anime has shown as capable of producing both silk and water bubbles.
Dewpider can only breathe oxygen dissolved in water, so the bubble over its head allows it to breathe on land. Additionally, the bubble provides protection to its soft head, and can be slammed into both prey and enemies. If two Dewpider meet, they compare bubbles and the one with the smaller bubble will move out of the way.
Multiple Dewpider debuted in Dewpider Ascending!, where they were told by their parent Araquanid to leave the nest and find their own places to call home. One Dewpider got separated from the group and came across Lana. Upon seeing Lana with a balloon on her head because of Popplio, it developed a crush on her. It then tried to find a new home, eventually finding one near the Pokémon School, but it had to battle a wildSurskit that already lived there. Dewpider lost the battle, but when Surskit evolved into a Masquerain, it happily abandoned its home and flew off, allowing Dewpider to live there. Earlier, it challenged two other Dewpider over territory, only to lose.
Dewpider can be seen as a counterpart to Surskit. Both share the Water and Bug types and the same base stat total of 269, both evolve at the same level, and both can be found at Brooklet Hill in Pokémon Sun and Moon, taking the place of the other depending on the time, with Dewpider being found during the day and Surskit at night.