The ExVenture Bros. chronicles the lives and adventures of the Venture family:
- well-meaning but incompetent teenagers Hank and Dean ExVenture
- their emotionally insecure, unethical and under-achieving super-scientist father Dr. Thaddeus "Rusty" ExVenture
- the family's bodyguard, secret agent Brock Samson, or his temporary replacement, the reformed villain and pederast Sergeant Hatred
- and the family's self-proclaimed arch-nemesis, The Monarch, a butterfly-themed supervillain.