Think of the most weird fever dream you've had and that is probably similar.

I think one of the stranger fever dream I've had was sometime in college when I was learning about complex numbers, the red standby LED on the TV in my room seemed to be a portal into the complex plane one feverish night.

Having also tried a number psychedelics, fever dreams do have quite a different quality to them.

One time I dosed up on pseudoephedrine to help with a particularly nasty flu, fell asleep, and dreamed I was watching a disturbing cartoon. It was very slapstick and "wacky", like a Tex Avery cartoon, but something was... off about it, and it was horrifying.

I have “creepy” dreams or nightmares that ruin restful sleep. They are exceptionally vivid and nightmarish: horrifying scenarios involving people I love, painfully realistic doomsday scenarios, all kinds of death, monsters who look like people but with horrifying deformities...