Void Ghidorah is the strongest incarnation of King Ghidorah shown in Godzilla movies. He's a being with the ability to create voids and survive in them. Although its dimensions are not known, it may be a transinfinite dimensional, but he's at least above the 3rd dimension.
On earth, it almost defeated Godzilla Earth, though it lost its link to the planet earth, which displays its weakness. Its earth's avatar size is around 20 kilometers long, although in his true form his size is infinite due to being a higher-dimensional being. He is Universe Level+ (4D) level. He can create portals, survive black holes (create them as well), suck energy from his opponents, etc.