Planet X and Planet 10

Long throughout history, both on Earth and in this thing, there have been hypothesizes of a ninth and tenth planet. This article is divided into two parts: for X, and for 10.

Planet X
Planet X is the name given to a hypothetical ninth planet beyond Neptune. For some time, Pluto held this role until 2006 when it was demoted due to similar planets near Pluto. As a tenth, eleventh, twelfth, thirteenth, etc. planet was discovered and named, it became hard to list everything and the classification was given.

Appearance
Planet X (or Nibiru, as it's often called) has no clear appearance, as the mythology's appearance can vary. Some variations suggest Nibiru may not be an Exo at all, or simply fauna that has taken on a humanoid shape. Nibiru may also not wear clothing or wear little, likely to hide itself.

Personality
Nibiru is often portrayed as being calm, nice or even friendly, though sometimes this is not always the case. Some depict Nibiru as an aggressive one wielding nothing but a weapon (the type varies between the myth) or even simply beating enemies down mercilessly.

Relations
Nibiru is often portrayed with a brown dwarf star named Nemesis, who seems to be it's guardian or relative. Nemesis is often portrayed as being unable to say more than one word, or have limitless forbidden knowledge on certain subjects. Nibiru and Nemesis are often treated as brothers in arms, if they are even male to begin with.

Planet 10
Planet 10 is the name given to a hypothetical tenth planet in the Solar System. Though contenders have come up (see Aliases), they often are (in order) a moon, four different asteroids, and three dwarf planets.

Appearance
Planet 10 is often portrayed as a generic male (sometimes female) Exo, or may even be portrayed as some kind of animal or a disgustingly detailed hybrid of Exo and animal. As ultimately it belongs to the person to decide the details, the exact appearance of Planet 10 is unknown.

Personality
There is no written personality for Planet 10. Although most chalk it up as simply running out of ideas, sometimes Planet 10 can be written as simply not having a personality or even a basic one (varying emotions, aggressiveness, etc.)

Relations
Planet 10 and Planet X are often written as comrades in arms should Nemesis not be part of the person's ideas. Although both Planet 10 and X are often written as unrelated, sometimes Planet 10 may have directly come from X through means.

Relation with normal Exos

 * Charon: Charon is sometimes teased around with the "Planet 10" label.
 * Sun: The Sun actively denies any proof of Nemesis or Nibiru, often chalking them up as just relatives who left to see other cities, often with vows of never coming back.
 * Earth: Earth hopes to prove Nibiru real, to the chagrin of Moon.