Hallucinogenic drugs are those drugs which alter the person's perceptions and awareness about its surrounding environment. Hallucinogenic drugs cause hallucinations in the person. During hallucination the person's senses percept those things that are not happening in real so he is not connected with reality during a hallucination.
Psilocybin is a hallucinogenic drug that is isolated from psilocybin mushroom or magic mushroom which is found in tropical regions South America, United States, and Mexico. It cause visual and auditory hallucinations which alters time and space perception.
So Psilocybin is an example of a hallucinogenic drug.
