Triton

Overview
Triton is the largest moon of Neptune and the 7th largest moon overall.

About this moon
Triton started out as a former Kuiper Belt Object. It was once also the largest dwarf planet in the solar system. Triton has proof why it used to be a Kuiper Belt Object. Triton has a retrograde orbit. Other moons have it too, but Triton is different. Since Triton is the largest moon of Neptune, it can't be natural. That could explain why.

What it looks like
Triton looks a bit like Europa in a way. Since it was a Kuiper Belt Object, it is an ice moon.

Facts

 * Triton is the only large moon with a retrograde orbit. Moons that have them are very small.
 * This moon along with Nereid could have been Kuiper Belt Objects. But with Nereid, it's orbit could have just been from Triton's capture.
 * Triton, Titania and Titan have all similar names.