Makemake is 2/3 the diameter of Pluto.
Average temperature is estimated at 30K (-243.2 C). That is cold. Well, it's quite far from the Sun.
It is believed to be covered with methane, ethane, and maybe nitrogen ices.
It was discovered in 2008, and promoted to be called a dwarf planet in 2008 by the International Astronomical Union. It was the fourth object recognized as a dwarf planet.
The team that announced the discovery, announced it before they confirmed their findings. And they did that because when they were tracking another object called Haumea, another team announced the discovery before they did. That's how it is in the science circles, folks.
This is the object that was nicknamed "Easterbunny" before it was given an official name, because it was discovered close to Easter.
It takes Makemake 310 years to orbit the Sun.
It is far enough from Neptune to not be effected by it and objects in Neptunian surroundings.
Makemake is considered to be part of the Kuiper belt, the collection of space objects beyond Neptune.
It is the second brightest Kuiper belt object. and probably the third largest object beyond the orbit of Neptune, after Pluto and Eris. Why probably largest? Because its size cannot be determined precisely. It has no moons, and the way to really find out an object's size is by observing its interaction with orbiting objects.
Image source: Hubble Telescope