Eris

Eris is the largest dwarf planet in our solar system, located in the scattered disc, a region of icy objects beyond the orbit of Neptune. It was discovered in 2005 and is named after the Greek goddess of strife and discord. Eris is about the same size as Pluto and has a highly elliptical orbit that takes about 558 years to complete.

Characteristics of Eris:

Size: Eris has a diameter of about 2,326 kilometers, making it slightly larger than Pluto.
Composition: It is composed mainly of rock and ice, similar to other dwarf planets in the outer solar system.
Orbit: Eris has a very eccentric orbit, which means it can be as close as 38.2 AU from the Sun and as far as 97.6 AU.
Satellite: Eris has one known moon, named Dysnomia, which is about 7% of the mass of Eris.