This is an in-universe article with out-of-universe material.
Cobb was born into a middle-class family, but when his father tragically died while building a bridge for Cameron Kane. Unable to support themselves, Cobb took to juggling baseballs on the street for pennies against his mother's wishes. His mother had worked at a textile plant but she alone could not support the two of them. She had told him not to "beg" on the streets. Cobb continued juggling anyway and snuck his earnings into his mother's purse when she wasn't looking. He continued this strategy for over a year. When one day, by chance, a thief on the street pickpocketed a man watching Cobb's juggling. Alerted, the man yelled for his wallet as the thief ran away. Cobb luckily intervened and hit the thief in the head with one of his baseballs. Thanking Cobb, the pickpocketed man offered the young boy a job at his circus.
The circus owner went to talk to Cobb's mother, who had known Cobb had been begging all along, about letting Cobb join the circus. Because of their money situation, she agreed, and Cobb went to work at the circus. The circus director said that the old "baseball routine" was not going to bring in audiences and handed him knives to work with. Over the years, William Cobb had become spectacular with knives. The crowd loved him. He managed to become a household name. Once a child living in Gotham, he was now a child of Gotham.
When he returned to Gotham City, a large crowd applauded their hometown celebrity. One woman caught his eye though. Her name was Amelia. She was the daughter of one of Gotham's elite and an original child of Gotham. The two fell in love at first sight. The two began dating and they were happy together. They were two children in love. Little did they know, Cobb describes, it was the beginning of the end, when it was revealed that while they were still dating, they were fooling around until the point marriage came up. One day when walking into her house, Amelia's father Burton Crowne asked to speak with Cobb. He told Cobb that there are only two people in life (the rich and the poor), no room for grey. Burton had banned Cobb from ever seeing Amelia again, but not before making her pregnant beforehand. Being so torn at the time, he accepted an offer to join the Talons by Nathaniel Haly, his circus boss. It is implied, using knowledge from earlier Nightwing issues, that Cobb was showed to the Court of Owls. They chose him to be one of the Talons and prepared him, giving him an electrum tooth. Cobb became a natural Talon. Making his rounds and becoming elite, he broke back into Amelia's house and stealing his then born son. Outside of the house, he met Nathaniel, handed him the baby, "Raise him with Haly in secret, Nathaniel...prepare him for my legacy. My son. The Gray Son of Gotham". This baby would become John Grayson's father, and his son, Dick Grayson's grandfather.
Sent to assassinate Batman, the two struggle off a rooftop and Talon plummets to his apparent death. On the drive to the morgue, he wakes up again and kills the driver before escaping.  His next attempt on Batman's life is a giant explosion destroying his own recently discovered headquarters.  Batman investigates the sewer when Alan Wayne's body was found, and Talon surprises then abducts him.  The Court holds Batman in a massive labyrinth for over a week with no food where he goes slowly mad, until Talon finally approaches from behind and stabs him.  They sentence Batman to death, and he delivers a brutal beating to the broken man. Finally the super-hero fights back with his last reserves of strength, and savagely takes the Talon down while his masters flee. Following Batman's escape, the Court of Owls decide to dispose of Talon. Despite his ability to physically recover, he will never mentally recover from the defeat. It is revealed that they have an army of similar warriors. 
Alfred and Nightwing later discover Talon's body adrift in the Gotham river and bring it back to the Batcave for further examination. Batman strips away the assassin's costume to reveal the body of William Cobb, great-grandfather of Dick Grayson! It seems that William was never truly dead, but rather kept in an odd form of stasis, neither living nor dead, and only awoken when the Court had need of his skills.  
Night of the Owls
While the Batcave was under attack by the other Talons, Cobb remained in his half dead/half alive state on the examination table.  However, he somehow broke free, possibly from assistance from some of the other Talons but this is unproven, and attacked Dick Grayson, his great-grandson, at the mayor's office. Though apparently evenly matched, in terms of training, and experience, Cobb's regereative capabilities, combined with Nightwing's injuries, sustained during his prior fight with another Talon, give Cobb the advantage. Cobb says that Grayson betrayed him by becoming a vigilante instead of a Talon like Grayson was supposed to be. Cobb, disappointed, throws four knives into his descendent, and waits over him, preparing to kill Nightwing. 
Nightwing manages to get away and proceeds to lead William on a chase through Gotham, and finally down into a subway station. The entire way, William expresses his disgust and disappointment with Dick for turning his back on his birthright to be a Talon, saying that Dick could have been the greatest of them all. Dick finally says he couldn't care less what his great-grandfather wanted for him and reveals he has led the undead assassin into a trap! He uses his escrima sticks to rupture a cooling pipe overhead, covering William in liquid Nitrogen and sending him back into hibernation. Dick picks up his ancestor's body and carries him outside, first stripping away his Talon mask and tossing it to the floor. 
- Increased Healing: Due to the the synthesized electrum in his blood, Cobb can easily survive intense pain. He, in his first encounter with Batman, was thrown off of Wayne tower and survived.
- Hand-to-Hand Combat (Advanced): The Court of Owls has forged William into a master hand-to-hand combatant. He is able to match Batman blow-for-blow.
- Throwing: A trained knife-thrower, William has uncanny aim with his knives, able to hit specific arteries and veins even in the midst of combat.
- Weaponry: William, like all Talons, uses an arsenal of bladed weapons on his missions, ranging from his signature throwing knives to full-sized broadswords and axes.
- Requires Electrum: When Cobb is defeated, he requires an alloy known as electrum to continue functioning. This alloy is supplied by the Court of Owls, but, if the Talon is defeated, they have the choice to cut off his supply.
- Paraglider Wings: The Talon, although never used, possesses deployable wings that allow him to glide. This is proven when the other Talons, who wield the same armor as Cobb, jump from the top of a building and glide away.
- Throwing Knives
- William Cobb is Dick Grayson's great-grandfather. This means that Grayson's great-grandfather possibly killed Wayne's great-grandfather but this is currently unproven.
- Cobb was born October 10, 1901.
- 32 Appearances of William Cobb (Prime Earth)
- 21 Images featuring William Cobb (Prime Earth)
- 6 Quotations by or about William Cobb (Prime Earth)
- Character Gallery: William Cobb (Prime Earth)