Poison dart frog
The most toxic of poison dart frog species is Phyllobates terribilis. As mentioned above, dart frogs do not make their own poisons, but keep (sequester) the chemicals from arthropod prey, such as ants, centipedes and mites. This is the diet-toxicity hypothesis. Because of this, captive-bred animals do not have significant levels of toxins: they are reared on diets that do not have the alkaloids used by wild populations.  Nonetheless, the captive-bred frogs can store up alkaloids if they get an alkaloid-containing diet.