Buzzwole is an Ultra Beast that resembles a large, anthropomorphic mosquito. Its head is small and flat with a black ridge up the center. It has two red compound eyes with two black, spherical basal joints for its red and black antennae between them. Protruding from under these joints is a long, silver proboscis. It has many bulging muscles that appear to be sacs full of a red fluid with small white bubbles inside. There are three sacs on each arm, two on each leg, two on its chest, and several on its shoulders and down its back. Around its waist are three rings of smaller sacs. The muscles on its chest and some on its arms and waist have thin, grayish lines resembling tendons running across them. It has large, five-fingered hands with red knuckles and four pointed legs. There are several black spikes on its body: a small one on each side of its head, two on each shoulder, one on each elbow, and one on each leg. The portions of its body between its muscles are dark red or black. On its back are two pairs of pale orange wings with slightly darker veins.
According to Wicke from the Aether Foundation, its most notable feature is its ability to strengthen itself. By stabbing its proboscis into a foe, it absorbs the foe's energy. This in turn triggers a chemical reaction within its body fluids that causes its muscles to grow at explosive rates, further augmenting its already considerable strength. Buzzwole appears to strike bodybuilding poses before it performs any sort of action. This is thought to be its main form of communication, but what it could be trying to communicate is not understood.
Buzzwole is based on a mosquito, given a strong muscular physique to contrast its real-world size and frailness. The specific kind of mosquito may be the Aedes albopictus, which is an invasive species worldwide.
Buzzwole's physique may be inspired by bodybuilders, or common depictions of superheroes in comic books. The black portions of its body resemble the shading in comic book illustrations used to draw attention to a character's musculature.
Buzzwole may be a combination of buzz and the slang word swole, meaning muscular.
Massivoon may be a combination of massive and 蚊 bun (mosquito) or ブーン būn (buzz).