I vividly hallucinate for a few minutes before falling asleep (sometimes 10+ minutes). It got so weird that I had to Google it a few years ago to make sure I wasn't going insane. I'd actually dread falling asleep because it wasn't always the most fun thing to have happening.

It used to manifest as people being in the room, loud talking, having conversations with people. I'd even tell people to shut up so I could sleep.

This was more common when I was drinking alcohol for whatever reason, and since being sober it doesn't happen as frequently. Being very sleep deprived is an easy way to trigger it though.

I still occasionally have to remind myself when it's happening that I'm not crazy.