Pluto (Planet)
Pluto was named after the Roman god of the underworld.
Pluto was a planet but lost it's rights due to the updated definition of a planet. After repeatedly finding more dwarf planets they revised the definition. Thus because pluto shares an orbit with other dwarf planets, it is not considered a planet.
Pluto is the largest known dwarf planet, however it is smaller than some moons.
Pluto has more than 3x as much water as earth (1/3 of Pluto is made of water).