[2] Most of the villains Gruenwald introduced in Captain America were created to symbolize aspects of contemporary American culture and the world political situation.

On the way to a picnic with his family and church community, their bus collides with a tanker truck full of Compound X07 (an experimental nerve agent developed by A.I.M.).

Everyone aboard the bus, including his parents and sister Katy, are killed, leaving him as the only survivor, his body mixing with the Compound.

Spewing absurdist philosophy, he runs rampant through the streets of Manhattan, causing mass chaos and a riot.

In the course of the fight he meets Dollar Bill, who runs a Manhattan public-access television cable TV show.

Madcap agrees, but his idea of adventure is to cause chaos and confusion all over town and even go head-on to confront armed bank robbers.

[8] Madcap is later captured by Vice and Triphammer of the Power Tools on the order of Dr. Karl Malus and is rescued by Hawkeye.

Madcap feels all the pain he has caused his victims and likes it: it is the first real sensation he has felt in some time, and he vows to continue, in order to experience the Stare again.

His bad Monty Python routines are interrupted by Deadpool, who temporarily defeats him with a blow that seemingly snaps Madcap's neck.

[16] Madcap later appears as a member of the Shadow Council's incarnation of the Masters of Evil, at the time when the Secret Avengers raid Bagalia to recruit Taskmaster to their side.

[18] Eight months after the events of Secret Wars, Madcap was revealed to have been psychologically damaged even further by his fusion with and separation from Deadpool.

[20][21] Madcap resurfaces during Civil War II as a parasitic entity that is forcing its human host to act against Deadpool.

[24][25] Deadpool acquires a cure to the virus and locates Madcap, whose host is revealed to be Bob, Agent of Hydra.