This was easily one of the absolute wildest dreams I've had in my life.
I was hanging out with some people I know at a really big house. Someone gave me some apparently sacred ancient Egyptian hallucinogen that, usually very mild, goes absolutely fucking crazy when artificially emitted images are within sight, and doesn't stop once they are. The drug itself was some syrupy liquid that was put into a gummy-like form. I was an idiot and took a really high-dosage one (which, with this substance, makes the trip stronger instead of just longer in duration). It was extremely hard to chew, tasted very bitter, and really opened up my sinuses for some reason.
The one who gave me it left and I went to another room with a computer to hang out and trip with a couple of other guys I don't really know well. We went to this web site we were showed that supposedly enhances the experience by displaying completely nonsensical, brightly colored animations and ACSII art designed for the drug.
After like 15-30 minutes the screen started getting crazy and I could no longer make out any of the words. It was kind of cool at this point, and felt pretty pleasant. A bit later it started just getting fucked up and I lost complete grasp of everything. I no longer had any idea what was going on, the screen started just displaying a shitload of images really fast, I started hearing loud incoherent deep voices telepathically communicating very negative messages, and I kept getting brief total hallucinations that blocked out all my senses, rapidly transporting me to one world after another for like a minute before I regained control of myself.
After this kept happening I started just losing it and freaking out, with the other two trying to calm me down. I went downstairs to walk around where everybody else was, and at this point it seemed like there was some illusionary creature following me and trying to gain control. I calmed down a bit, and all the really fucked up stuff stopped happening. I checked my iPod and instead of my background, a picture of Charlie Tagawa, I started just getting rapid-fire flashes of random photographs of older men I've seen throughout my life (most of them were black-and-white and grainy beyond recognition).
I returned to the room I was earlier, and as soon as I sat down I saw an extremely vivid silhouette of a woman. It was glowing dark blue, and had swirls of red, purple, and green among other colors. The silhouette spoke, and though I couldn't comprehend its voice, I understood that it was telling me it was a goddess and that it had created humanity.
At this point everything started calming down. I ended up in what appeared to be my school and I heard what I believe to be random sound clips from the first few Harry Potter movies, among other audio pulled out from my memory. Everything else is a blur beyond this.
I don't know how the fuck this dream could have happened, but it was somewhat enlightening, and it was definitely a good warning to take it slowly and safely if I every try drugs. It's good that there were no consequences this time.