Little is known about this villain. At one time he was a crinimal mastermind and leader who could shoot powerful Opti-Blasts from his visor. These blasts could temporarily or permintanly blind a person. He has fought Daredevil, Spider-Man, and Iron Man. He also had short team-ups with their other foes, Gladiator and Stilt-Man. He has even joined the ranks of Maggia.
When Stilt-Man was killed by Punisher during the Civil War, Marauder came to his funeral in the Bar With No Name along with many other costumed criminals. Punisher, who was the bartender, poisoned all of the villains drinks and put c4 around the building, then blew the place up. Marauder survived though, and was later seen helping the Hood's gang against the Skrulls in the Secret Invassion story arc.
He has a brief cameo in the Netflix Daredevil series. The prison guard tasked by Wesley with killing Karen Page is named Mr Farnum. Karen is saved by Daredevil though, and Farnum is killed by Kingpin's men.