Blanets are hypothetical class of planets that orbits around super-massive black holes, which are found at the heart of most galaxies in the Universe. These are black holes with a mass above 0.1 million to 1 million solar masses. In 2019, a group of astronomers led by Keiichi Wada of Kagoshima University in Japan showed that there is a safe zone around a black hole, where it could harbor hundreds of thousands of them.
According to this new idea of Wada and his colleagues, "blanets" would form from dust and gas orbiting super-massive black holes (SMBH). In this scenario, they would form about 5-20 light years away from the SMBH and they would take over a million year to complete their one orbit. These Blanets would be more massive than Earth and up to Jupiter-size however they would be rocky and hard as Earth. They are formed in the accretion disk beyond the snow line of a super-massive black hole, where space is cold and ice particles can exists, which is an important ingredient in planet formation. When these ice particles will collide, they will stick to each other. Their gravity will pull each other and they will get bigger and bigger when they will collide and stick to each other. Once these clumps grow big enough, they will become rocky planets in about 10 million years. If these ice clumps attracted more gas then they will become gas giants.Check here