Baron Silas Greenback is the main villain of Danger Mouse. A very powerful toad and criminal mastermind he is behind innumerable schemes to cause trouble across the world and was a parody/homage of various spy villains (especially 007 villains) - he rarely got his own hands dirty however and prefered to have his many minions do his tasks while he sat and gave them orders, he was often seen with his pet caterpillar - which he treated like a cat.