No body knows exactly how many mushrooms contain compounds that when ingested produce hallucinations, however I think there are around 215 known species currently recognized, more will surely be discovered.
A few of them grow in manure however a large number prefer different habitats; lawns, wood chip piles, dead wood, etc. The last time I saw a fruiting of hallucinogenic mushrooms they were growing terrestrially from the well manicured lawn of a church -- the irony sort of pleased me lol.
Most hallucinogenic mushrooms contain a compound called psilocybin, along with a few similarly structured molecules. Magic mushrooms from this category are generally considered to be relatively nontoxic from the physiological perspective, however they can have pretty darned profound psychological impacts.
The magic mushrooms of the genus Amanita are known to be far more toxic -- to the point of being quite dangerous. The genus Amanita is home to hundreds of species including some of the most deadly mushrooms on the planet.