The highly psychoactive molecule N,N-dimethyltryptamine (or simply DMT), is found naturally occurring in the brains of humans, mammals, and some other animals, as well as in a broad range of species of the plant kingdom. Although speculative, neurochemical research suggests that DMT may be made in the pineal gland, and it is hypothesised that, as much as melatonin helps activate sleep cycles, DMT activates- dreaming, and may also be implicated in other natural visionary states such as mystical experience, near-death experience (NDE), spontaneous psi and psychosis. Amazonian shamans may have made use of this chemical for its visionary properties for thousands of years, and take it as part of a decoction frequently called ayahuasca, which translates from Quechua as "vine of the spirits" or "vine of the dead". The psychedelic brew is taken because it gives rise to extraordinary mental phenomena that have shamanic and supposed healing qualities, such as synaesthesia, ostensible extra-dimensional percepts, out-of-body experiences, psi experiences and, perhaps most commonly, encounters with discarnate entities. When described by independent and seemingly naïve DMT participants the entities encountered tend to vary in detail hut often helong to one of a very few similar types, with similar behavioural characteristics. For instance, mischievous shapeshifting elves, praying mantis alien brain surgeons and jewel-encrusted reptilian beings, who all seem to appear with baffling predictability. This opens up a wealth of questions as to the ontology of these entities. The discussion of the phenomenology and ontology of these entities mixes research from parapsychology, ethnobotany amd psychopharmacology — the fruits of science — with the foamy custard of folklore, anthropology, mythology, cultural studies and related disciplines. Hopefully, however, given the varied readership of this journal, it won't prove to be a trifie too interdisciplinary.