Neutron star is a very dense planet, its mass is about 1.4 times that of the sun, but its radius is only about 10 km. The gravity of neutron stars is so strong that even light cannot escape, so black holes may be sucked in by neutron stars. Neutron stars are the densest stars except black holes and can compete with black holes. If the neutron star is thinner, then the black hole may devour the neutron star, so it is considered that the neutron star is the natural enemy of the black hole.
The planet a black hole fears most is a white dwarf. There are many rock stars around the white dwarf, and these rock stars are very small. Every time the white dwarf rotates, it will instantly chew up the asteroid, which shows that the white dwarf has the ability to decompose and obliterate celestial bodies in other universes. If a black hole passes through a white dwarf, it may also be decomposed, and it is also a planet that black holes are afraid of.