Here you go guys:
Palytoxin was first isolated from the soft coral Palythoa toxica. Several species of Palythoa are used in aquariums, but do not produce the toxin.
Originally, it was only found in a single tidal pool on the island of Maui in Hawaii and native Hawaiians used to coat spear points with a red seaweed from the pool. Toxin-containing corals appear to be randomly and sparingly distributed throughout the South Pacific and there is now a school of thought that suggests that the coral is simply concentrating the toxin made by a dinoflagellate (a small single-celled organism) called Ostreopis siamensis.
Palytoxin is the most toxic natural product known, it is estimated that the lethal dose for a human is less than five micrograms. Supplies are extremely limited as it is only found at low concentrations in the corals that do contain it
, although this may change if a microbial source is found.
....thought I'd also add, that being poisoned by this stuff sounds horribly terrible!