Baxster is the biggest black hole ever discovered. It is as large 812 quindecillion of solar masses, that is 729.124.347.241.973.124.544.182.287.411.712.366.688.212.862.612.271.748.429 KM.
It is located in the begaverse, in the area of the holeverse.
It is twice the size of the whole observable universe and is made of the main material of which black holes are made.