Aflatoxin is a type of mycotoxin produced by Aspergillus molds. Aflatoxin is probably the most well known mycotoxin, besides trichothecene, and the most researched.This is because aflatoxins are very toxic and highly carcinogenic.flatoxin mycotoxins are produced by the Aspergillus species of molds. Aspergillus molds grow mostly on crops, such as grains and nuts. Under the right conditions, Aspergillus often grows on grain before it is harvested. But it can also grow on harvested grain if the grain is stored damp.