Dewott is a bipedal, otter-like Pokémon that is primarily light blue in coloration. It has small black ears, a pointed crest at the back of its head, a red nose shaped like a tilted oval, and long white whiskers forming tilted "V" shapes. Its forelimbs sport three fingers on each black-colored paw. Around its waist is a large, blue, fringed adornment, with seashells—like those Dewott possessed as an Oshawott—on the thighs. Its feet are tipped in black and its somewhat plank-shaped tail is also black-colored.
Dewott can detach the two shells from its hips and use them as bladed weapons. Swordshell-wielding attacks differ between Dewott.
Dewott strictly train themselves to be able to master its shell swordsmanship. It never fails when keeping its swordshell in shape.
Dewott primarily live in water, but are actually amphibious, like Oshawott and Samurott.
Dewott is a combination of dew or duo, water, and otter. Futachimaru seems to come from 二つ futatsu meaning two, 太刀 tachi meaning long sword, and 丸 maru, a common ending in a boy's name, especially in the time of samurai. The 二 futa in Futachimaru may imply a lineage within the evolutionary line, with Dewott being second in line.