Dr. Kojiro's thirty-first robot master Poison Man was based on the theme of a poison dart frog - specifically a yellow-banded poison dart frog. He was intended by the mad doctor to be an improvement upon Dr. Wily's Toad Man (though technically it was a Cossack design) as Kojiro was hoping to prove to himself to be better than "that old fogey" after his three prior defeats began to get him down. Unlike his inspiration, Poison Man is capable of damage over time through an ability to cause both acidic and rusting damage.