Final answer:
The indole found in toad skins that is not a very potent psychedelic is bufotenin.
Step-by-step explanation:
The indole that is originally found in toad skins and turns out not to be a very potent psychedelic is A) bufotenin.
Bufotenin is one of the several tryptamines found in nature which is a structural derivative of serotonin and melatonin and is found in the skin of some species of toads, in mushrooms, higher plants, and mammals, especially in the genus Bufo. Although it has been shown to cause hallucinations, it is considered to not be very potent compared to other hallucinogenic substances like DMT (Dimethyltryptamine), muscimol, or mescaline.