Ochiba Cricket

Ochiba Crickets (落ち葉蟋蟀, Literally meaning: Leaf Little Cricket) are a breed of poisonous cricket found only in the Land of Rainforests. They are eaten by certain shinobi of Edagakure in order to be able to secrete poison from their skin, which is necessary for the Poison Fist taijutsu fighting style. The poison itself is highly toxic and only requires skin to skin contact to be fatally dosed.

In order to for a person to secrete poison, they have to eat a large amount of the crickets over a three year period and then afterwards they have to eat them on a semi-regular basis for the toxins to remain deadly. However, once the user gains the toxic secretion, there is no way to remove it, so they have to be careful when out in public.