He is the central character in the episode The Man Who Killed Batman.
HistoryDebris was an incompetent henchman who tries to become a big shot but always fails his crimes. One night, Debris's friend Eddie G. had him to become a lookout of a drug deal and gave him a nickname Sid The Squid. In truth, they brought Sidney to distract Batman. After The Dark Knight corners and interrogates Debris while the others began their drug business, Sidney, in a clumsy manner pushes Batman and makes it look like he's fighting him. After their "fight" Sidney almost fell off the building he and Batman were on and struggled to grab Batman's hand. After Sidney accidentally knocked him off, Batman fell on to a propane tank that exploded. Eddie and the other mobsters saw the explosion and were stunned to see Debris holding Batman's cowl and quickly realized that he had murdered Batman.
Sidney later earned the title "the man who killed Batman." Eddie and the other mobsters celebrated Sidney's victory over Batman at a bar. For a short time, Sidney liked his title and fame and many criminals said that he's the toughest guy in Gotham. Though, there were some that wanted Sidney's title and challenged Sidney. Although Debris was actually a weak man, he attempted to flee his opponents but it caused a bar fight between his allies and those who challenged. The bar fight was brought to a halt by the police and everyone involved was arrested including Sidney. Debris was later bailed out by Harleen Quinzel in disguise as a lawyer. She later presented Sidney to The Joker. The Joker doesn't believe Sidney killed Batman and decides to pull a robbery to confirm weather he's really dead or not, however, Batman never arrived to stop him, saddening Joker. After eluding the police, Joker took Sidney to the ACE Chemicals factory to have a funeral for Batman, however, Joker then had his men stuff Sidney into Batman's coffin and roll it into a vat of acid.Sidney, miraculously, was saved when the coffin was washed away to shore. He later went to Thorne to help him get out of Gotham City, but Thorne thinks that Sidney wants to take over his criminal empire by acting dumb and later tries to kill him. However, Batman, who turns out have survived the explosion, defeated and stopped Thorne. Batman revealed to Debris that he pulled away from the explosion at the last second and has been following him so he could get information about Thorne's drug ring, revealing that he also saved him from Joker's wrath. Batman grabbed Debris and told him he was an accomplice in the drug ring therefore needs to go to jail, however, he notes a man of Sidney's reputation could get a lot of respect in prison. While in jail, the inmates of Stonegate cheered him for nearly killing Batman, making a fool out of The Joker, and tricking Rupert Thorne and Sidney finally accomplishes his goal of becoming a big shot.
- Sid the Squid was popular with the Warner Bro. writers they made it an alias for Slappy Squirrel.
- Sid the Squid was also an alias used by Tony Zucco.