Chi-Yu is a fish-like Pokémon. It is composed of two pairs of curved jade beads, once believed to be sacred and commonly worn for religious rituals. Each of these pairs of beads circle a black orb coated by white around the sides; together, they make up the eyes of Chi-Yu, while the rest of its fish-shaped body is formed by a dark red and yellow flame. The beads sometimes glow red and yellow when it attacks.
Like the other Treasures of Ruin, Chi-Yu's true form is the beads forming its eyes, having been given life by the envy of those who desired them enough to start wars over them — while its body is a form it has constructed using its control over fire. Chi-Yu's flames burn at over 5,400 degrees Fahrenheit (3,000 degrees Celsius), allowing it to melt rock and sand into lava that it can swim through. Chi-Yu typically levitates and flies around in the air despite its fish-like appearance. It is known as the Beads of Ruin.