Tritonball is a moonball of Neptuneball.
It orbits Neptuneball backwards, meaning it could've been a dwarf planet caught in Neptune's gravity (Plutoball's brother?). He misses his freedom, but being considered a moonball is a higher honor than being dwarf planetball, so he's okay.
Can into ice and geysers on his surface. In 3.6 billion years Triton will crash into Neptune or form a ring, making rings which cross over each other (if the other rings still exist).