Rorschach, also known as Walter Joseph Kovacs, is a masked detective that made his first comic book appearance in the graphic novel Watchmen.
Rorschach was born as Sylvia Kovacs to a prostitute. She was very resentful and cruel to him, and he wound up a very violent and aggressive child. After partially blinding another child for calling him "Whoreson," Kovacs was taken from his mother and raised at an institute for troubled children.
When he was told of his mother's death, the only thing he had to say was "good."
Kovacs ended up working in the textile industry once he left the orphanage. It was menial work, but he didn't complain. Eventually, he was assigned a dress made out of a special fabric developed by Dr. Manhattan: black and white fluids moving and changing between two layers of latex. Kovacs was captivated by the beauty of the fabric, and kept the dress when it was turned down by the client.
Some time later, he had read that the original client who dismissed the dress as "ugly" was murdered outside her home while her neighbors watched and never called the police. Ashamed for humanity, he cut up the dress into a mask, and donned the crimefighting persona of Rorschach.
Shortly after coming onto the crimefighting scene, Rorschach made good friends with the second Nite Owl, and together, they busted up the Big Figure's gang in the sewers of New York. When the Crimebusters were first attempted, Rorschach was eager to do as much good as possible. After the first (and last) meeting disbanded, he and Nite Owl continued to do good.
Then, on a routine kidnapping case, Rorschach witnessed something truly horrifying, and was transformed. What little innocence and good that had blossomed since his meeting Nite Owl was burst, and he saw the darkness that dwells within humanity. He became much more violent and much more solitary, and was considered paranoid by the other heroes.
In WatchmeX volume 1, Rorschach returns from the dead after obtaining powers similar to Doctor Manhattan. Rorschach visits Manhattan on his new planet of Xexius, where Manhattan has just finished creating a new breed of creature inspired by Veidt's squid alien in order to enact a genuine invasion of earth. Rorschach confronts Manhattan on the newly created planet, and the two titans engage in an epic battle that splinters the planet into two halves and seemingly kills Manhattan. The two planetary halves split apart, one flying straight into a nearby star. It is not revealed whether the remaining half contains any squid alien life.