The name of the opposite planet could be coined as the "Extraordinary Anti-Planet." Unlike an ordinary planet, the extraordinary anti-planet would possess unique and intriguing characteristics. While ordinary planets are typically solid masses that orbit a star, the extraordinary anti-planet would be composed of antimatter. Antimatter is the counterpart to regular matter, consisting of particles that have opposite charges. The extraordinary anti-planet would exhibit antigravitational properties, making it gravitationally repelling rather than attracting like an ordinary planet. This repulsive force would cause it to repel other celestial bodies, including ordinary planets, creating a remarkable interaction between the two. Similar to an ordinary planet, the extraordinary anti-planet would have its own atmosphere, albeit a fascinating one. Due to the antimatter composition and the unique properties associated with it, the anti-planet's atmosphere would likely possess strange and mesmerizing phenomena, such as antimatter storms or antimatter-powered weather systems. The surface of the extraordinary anti-planet would also be distinct from that of an ordinary planet. Instead of solid land masses or liquid oceans, the antimatter composition might give rise to vast expanses of exotic antimatter elements or antimatter plasma. These extraordinary features would make the anti-planet an anomalous sight in the cosmos. In summary, the Extraordinary Anti-Planet is a hypothetical celestial body composed of antimatter, exhibiting antigravitational properties and gravitationally repelling other objects. Its name suggests its unique nature and sets it apart from ordinary planets.