I think that you can hallucinate while high on cannabis to an extent. One time, since I always listen to music when I go to bed stoned, I was laying in my bed when I felt like someone was pounding on my bed from underneath, and I was convinced there was someone under my bed, even though I was too scared to look. I ended up sleeping on my couch because I was too paranoid to sleep in my room.

Also, I thought up this amazing music video while I was stoned for "I'm Your Bass Creator" by Basshunter that had something to do with dinosaurs and little people who floated around instead of walking.