Speed King has a humanoid appearance. It possesses a mannequin-like body and a human-like face with holes for eyes (later depicted as goggles) and a flat raised surface resembling a nose, as well as a fisherman's cap with several metal spikes along the brim and various strings of equal length sticking out from both sides. It has two large horns on each side of its head, a wide mouth, bearing gritted teeth along with pores and bumps over its 'skin'.
It appears to have robotic joints across its arms, and a fur-covered vest-like torso. Speed King's body becomes very skeletal and robotic below chest-level, lacking much of an abdomen and instead having metal bars and other apparatuses connecting it to its lower body.
Speed King is bright orange and red in the colored manga.
Little is known about Speed King's abilities but it is clear that its heat powers are lethal at both close and long range.
Speed King is shown to be physically able enough to rapidly pummel enemies, but the extent of its power is still unknown.
As explained by Jobin, Speed King has the primary ability to store heat and temperature within a short localized point, from single objects such as the surface of paper money or even a particular spot on the human body. However, the heat can then be transferred to anyone who touches said point where the heat is stored. Speed King can only affect objects within 10 centimeters, but it is shown that said objects can travel far away from Jobin and still be affected by Speed King's heat storage. For instance Ojiro Sasame could travel from the Higashikata House to downtown Morioh and still be affected.
Since Jobin can heat sodium chlorate enough to produce oxygen, it can be inferred that it can raise the temperature to at least 300 °C. He has used it to melt the wax stuffed into his beetles after brushing them with a paintbrush and has given Josuke a nosebleed simply after offering some tissues to wipe his face with. This power can be weaponized and used to heat people's blood vessels, boiling the blood inside to render them unconscious or even kill them, when applied to the temples the heat can become so damaging the eyes burst.
- Like all other Stands used by members of the Higashikata Family, its name includes the word "King".
- Yuya Fungami, a character from Diamond is Unbreakable, has the words "Speed King" emblazoned on his tie.
- The "Mera" part from its Stand Cry is a Japanese onomatopoeia for burning flames.
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