Leland Owlsley was once a successful financier and financial investor, nicknamed "The Owl of
Wall Street" for his financial acumen, until his
tax evasion and crooked business deals were exposed by the
Internal Revenue Service (IRS). Rather than fight the charges, he fled to a hideout across the
Hudson River and pursued a new career as a
crime lord. Owl had already been pooling a percentage of his earnings into researching superpowered enhancements; the result was a serum that enhanced his physical prowess and gave him the ability to glide. He subsequently employed two enforcers and captured
Daredevil in a chance encounter, planning to kill him at a meeting of underworld bosses in order to make himself the undisputed overlord of crime. However, Daredevil escaped and confronted Owl in battle. Eventually determining that he could not defeat Daredevil unarmed and alone, he fled, escaping his foe in the river. When he came to shore, Owl was captured by police, convicted, and sentenced to prison by Judge Lewis. Following an escape, Owl established a new hideout on a volcanic isle and kidnapped Judge Lewis and Matt Murdock (Daredevil's alter ego), forcing them to participate in a sham trial with Murdock forced to defend Lewis. With a clever distraction, the lawyer was able to change into Daredevil. Owl's second confrontation with his nemesis ended in a draw, and both were forced to flee the erupting island. He was later freed from prison by Mr. Kline, who ordered him to capture Daredevil. Learning from their previous encounters, Owl finally overcame Daredevil and sent him plummeting to his death. However, the vigilante was saved by
Black Widow, and the two of them worked together to thwart Owl's planned heist of the San Francisco public treasury. Owl was later stricken with a debilitating ailment resulting in the paralysis of his legs. Owl is fitted with a neurological pacemaker to cure his ailment. He battles Daredevil and
Spider-Man and is incapacitated when his pacemaker short-circuits. Owl is confined to a life-support module designed by the
Maggia. He schemed to loot New York under cover of a citywide blackout, but was captured by Spider-Man, the Black Widow, and
Simon Stroud. No longer confined to the module, Owl later engages in a gang war against
Doctor Octopus in an attempt to usurp
Kingpin's position as the crime boss of New York's underworld. Owl started to re-establish his presence in the criminal underworld in the absence of Kingpin. When Spider-Man visits him regarding information about the kidnapping of
May Parker, Owl says that
Electro and the
Vulture kidnapped her. This turns out to be a ploy by Owl, who is after the two villains for stealing from him. Owl begins to enlarge his criminal empire by refining Mutant Growth Hormone from his own genetic material, though Daredevil was able to get him arrested. He managed to manipulate behind the scenes and get the Kingpin arrested for a past murder when it looked like Fisk was going to make a deal with the FBI. The deal in question involved Matt Murdock being arrested for being Daredevil. When
Foggy Nelson, representing Murdock in court, visited him in jail, he was apparently killed by the other prisoners. Owl later taunted Murdock about this, and Murdock, who had become unhinged due to his friend's death, brutally beat Owl. Unbeknownst to the two of them, Nelson was alive and in witness protection. The
Sinister Six (consisting of
Boomerang,
Overdrive,
Shocker,
Speed Demon, and
Beetle) assaulted Owl's base. Overdrive and Speed Demon were captured by Owl and interrogated. Beetle tried to blackmail Owl into releasing them while covertly dialing for backup. Unimpressed, Owl got ready to execute her when Tombstone arrives. After a series of failures, Boomerang teams up with Owl and forms the Sinister Sixteen to retrieve the picture of Doctor Doom that the former had stolen a few days before, and that was now in the hands of the Chameleon. The line-up consisted of the dregs of the underworld, who Boomerang used as cannon fodder to retrieve the painting. During the "
Gang War" storyline, Elektra is visited by Owl, who states that several crime lords are vying for control over New York City. Owl later visits
Madame Masque, informing her that he hedged the heroes as she instructed. Owl is attacked by
Bellona and imprisoned alongside
Count Nefaria,
Hammerhead, and
Silvermane. Masque places Owl under mind control and forces him to battle Spider-Man. ==Powers and abilities==