Which butterflies are poisonous?

No butterflies are so poisonous that they kill people or large animals, but there is an African moth whose caterpillar's fluids are very poisonous. The N'gwa or 'Kaa caterpillar's entrails have been used by Bushmen to poison the tips of arrows. When shot by one of these arrows an antelope can be killed in short order. Other butterflies whose caterpillars eat poisonous plants such as milkweeds, pipevines, and passion vines, are distasteful and can cause birds who eat them to vomit or spit them out--never to try another.