I think that a black hole could technically form when a star runs out of hydrogen fuel to fuse together to make helium. When it runs out, you can get a gravitational collapse, where the star sort of falls in on itself. I have a feeling that this only happens with really HUGE stars, and I don’t know whether any variety of dwarf star would be big enough.
Basically, I’m as curious as you, with no answers to offer! OK, you can have Space Boy, or Neutron Star Dude. You decide. I’ll go and ask them both in the meantime!