The Knot Tops were a New York City gang, or perhaps a youth subculture replacing the skinheads of our world in the 1980s, characterized by wearing their hair in knots resting on the tops of their heads Japanese style. They were quite violent and vicious; while walking to Hollis Mason's home, Dan Dreiberg and Laurie Juspeczyk are attacked by a small group of them in an alley. Dreiberg and Juspeczyk fight them off, severely injuring them. This instance has later repercussions for Hollis Mason, as the Knot Tops later credit one of these gang member's paralysis to Hollis Mason.
Knot Tops frequently use recreational drugs, especially KT28s or "katies". These seem to exacerbate the youths' already aggressive behaviour.
The Knot Top image is adopted by some musicians, notably Red D'Eath of Pale Horse and also by some upper-class sophisticates, as seen in the case of the woman in a smart evening gown sitting down to a genetically modified turkey at Rafael's; her hairstyle combines Knot Top and skinhead elements.
The Knot Tops murder Hollis Mason on Halloween, when they also mistakenly believe that Mason was the Nite Owl that freed Rorschach from prison. This small group was led by a man named Derf. Those involved were under the influence of katies at the time.