Kilowattrel is a large avian Pokémon. Its feathers are mostly black, with a grayish dark blue lower body, and yellow colorations on its wings, near its eyes, and on its neck. The latter contains Kilowattrel's throat sac, and has zig-zag patterns on the sides of the neck where the sac connects to. Kilowattrel's eyes have light blue irises and black pupils. Its long, hooked beak, along with its feet, are maroon in color. Each of its feet has three toes on the front and one on the back. Its thin, lengthy tail feathers are split into two.
Kilowattrel uses its throat sac to store the electricity that its wings generate, and can inflate the sac in order to amplify this electricity. When inflated, Kilowattrel's throat sac glows like a light bulb. Kilowattrel can fly over 430 miles (700 km) within a single day by riding the wind. However, it cannot swim very well in water, due to a lack of oil in its feathers.
Kilowattrel and its pre-evolved form, Wattrel, are the only known Pokémon that can have Wind Power as an Ability.
Kilowattrel may be based on a frigatebird. Like frigatebirds, Kilowattrel has a hooked beak, angular wings, and forked tail. Its large wingspan and size might also reference the fact that frigatebirds have the largest wing area to body ratio of any bird. The throat sac of Kilowattrel also resembles the gular sac found on male frigatebirds. Much like its pre-evolution, it may also take inspiration from storm petrels.
Kilowattrel may be a combination of kilowatt and petrel.
Taikaiden may be a combination of 大 tai (big; great), 大海 taikai (ocean), 海燕 kaien (northern storm petrel), and 雷電 raiden (thunder and lightning).