Naganadel's main stinger can eject a powerful, adhesive, and luminescent poison at a distance of over six miles. The abdomen contains hundreds of liters of this poison, as well as the Ultra Beast's brain. The stingers on its abdomen are directly connected to its brain, and it will react with violence if they are touched by anyone.
Naganadel is a large purple striped Pokémon that has both draconic and insectoid features. The top half of its body is slender with thin arms and fuchsia tipped claws. Both shoulders have grey spikes. Naganadel possess purple draconic wings, which it uses to fly. These wings have a single fuchsia claw at the joint and darker purple membranes. At the end of its long neck is its head, which has a large spiked crest and grey face spikes which act as mandibles when it opens its mouth. Its glowing cyan eyes are conjoined, giving the appearance of a visor. The lower half of its body is an abdomen that resembles a wasp's abdomen. There are three grey spikes on the end of the abdomen, with the middle one being the largest and resembling a hypodermic needle or a wasp's stinger.