The core.
The heart of the planet is called the core, Earth's core is molten while some other planets have solid cores.
Heart of Courage by Invincible
There is no planet that is called the "glossy planet".
The center of the planet is called the "core."
Mecury is not called the red planet. Mars is called the red planet because of the iron oxide (rust) in it's soil, making the planet look red. Yes, Venus is the hottest planet but it is not called the red planet.
The planet Uranus is called an ice giant planet.
Jupiter is called the giant planet
no
The fictional planet Tralfamadore is the moon of a large planet called Tran.
A moon? I don't think a planet orbiting another planet would be called a planet.
We are called Earth. "Blue Planet" is a nickname for Earth, since our planet comprises primarily of water.
The "Sun" isn't called a planet. It's a Star.
A Planet Called Utopia was created in 1979.