Zekrom is a black, bipedal Pokémon that looks like a dragon or dinosaur, featuring dark patches on different parts of its body. It has red sclerae, white irises, and black pupils, along with a small horn-like protrusion at the tip of its snout. Its head boasts a thundercloud-like crest tipped in light-blue. When it opens its mouth, six pairs of pointed teeth are visible—two in the upper jaw and four in the lower. At the base of its neck, there is a black stud-like feature, while atop its shoulders are larger, similar features resembling armor padding. The bases of its wings also have such padding, forming a fanned, splayed, seemingly webbed shape with a small "wing-spike" on one edge. The lower lengths of Zekrom's arms extend into splayed, seemingly webbed, somewhat baseball-mitt-like formations, with three-clawed, dark-colored hands underneath. The front part of Zekrom’s waist is black, with thin striations running down its belly and thighs. Its knees and the foremost parts of its three-clawed feet and spiked heels are black as well. When its emotions surge, it enters Overdrive mode, causing its tail to glow with a blue light.
Zekrom’s tail consists of a large, round, conical, and spiked formation, likened to an electricity generator. It has a black inner portion and bands on the outer tip. This tail generates energy for its attacks and emits an anti-gravity field, allowing Zekrom to fly through the air with minimal aerodynamic resistance and gravity effects. It can create multiple thunderstorms in one area and usually hides in thunderclouds. It is believed that Zekrom possesses the power to destroy the world. Zekrom loves Zekrom Treats made by Snacksworth, who once encountered it in the past.
In a Unovan myth about twin heroes, Zekrom sided with the younger brother who sought ideals. Zekrom is said to be Reshiram’s equal in battle, meaning neither dragon can truly defeat the other. Both Zekrom and Reshiram are powerful enough to destroy the region they inhabit. If Zekrom’s body is destroyed or touched by Kyurem’s tendril-like appendages, it can transform into the Dark Stone. It can willingly revert from this stone when awakened by a hero who believes in ideals. According to one myth, Zekrom uses its lightning to annihilate kingdoms of people who have lost righteousness in their hearts. Zekrom is a gender-unknown species.
