Professor Pyg was a serial killer operating in Gotham City, who was eliminating criminals and police officers on Penguin's payroll in order to combat corruption. Detective Gordon and Captain Bullock tracked Pyg to an abandoned factory, where Pyg killed an officer with a grenade, knocking out Gordon and Bullock in the process. Pyg slashed Bullock's throat, ensuring his getaway as Gordon stayed behind to help his partner.
Pyg proceeded to infiltrate the GCPD as an officer named Fisole, pretending to be captured by Pyg and injuring himself. Gordon goes with Fisole in an ambulance, and Fisole points Gordon to an abandoned courthouse where he thinks Pyg went. Captain Bullock, with pressure mounting due to a partnership with Penguin, demands the GCPD storm the courthouse, despite Gordon receiving a threat from Pyg that going inside meant death for the officers. Inside the courthouse, several GCPD officers are wounded by a machine gun and Bullock himself shot the officer they were trying to save.
Pyg posed as a rabbi and fed poisoned food to homeless people, in order to harvest their organs and bake them into meat pies. Pyg calls Gordon, who managed to trace Pyg to an abandoned paper factory. However, Pyg kidnaps Gordon's new partner Detective Harper and takes the place of chef at Sofie Falcone's charity event, where Penguin and Gotham's rich elite are attending. Gordon tracks Pyg to the event, but is tied up and Pyg is planning on baking him in the kitchen oven. Pyg forced the elite to eat the meat pies he made, and Penguin is the first to comply, not wanting his new friend Martin to be killed by Pyg. Harper, who has evaded Pyg, finds Gordon tied up and saves him before Pyg can put him in the oven and eat him. They interrupt the meal together, battling Pyg and stabbing him. Pyg was then brought in to GCPD custody.
Gordon went to visit Pyg in Arkham in order to try and work out his true identity. When Gordon mocked Pyg back stating that he would be a forgotten criminal and not on the same level as big shots such as Oswald Cobblepot, Jerome Valeska and Fish Mooney, an angry Pyg retorted back in a Southern accent, which gave Gordon an idea where he was from. Pyg managed to escape from Arkham, leaving behind a message in a guard's blood aimed at Gordon, saying that he would see him soon.
Pyg's real name is revealed to be Lazlo Valentin, a hitman who copycats other serial killers. He was hired by Arthur Penn on behalf of Sofia in her goal to takeover the criminal underworld and to get her revenge on Gordon, for him killing her brother Mario. Lazlo was present when a group of gunmen assassinated Sofia's father Carmine Falcone on her orders, which allowed her free reign to takeover his criminal empire without his interference. During the shootout, Lazlo non-fatally shot Sofia, in order to detract from her being a suspect in killing Falcone.
When Gordon confronted Sofia at her home, Lazlo arrived and revealed he was in cahoots with her all along. With his usefulness out of the way, Sofia shot Lazlo dead, and Gordon called it in as self defense, as he didn't want anyone knowing that he was indirectly responsible for the Pyg coming to the city (due to him calling upon Sofia for help to get rid of Penguin).
One year after his death, Professor Pyg appeared in a nightmare of Jim Gordon, who was having a near-death experience after getting shot by Victor Zsasz. Lazlo, Kathryn Monroe and Scarecrow were among Gordon's greatest adversaries who attended his funeral at the GCPD Headquarters.
- This version of the character is exclusive to the continuity of the television series Gotham and its tie-in webseries and shorts, Gotham Stories and Gotham: A City Gone Mad. It is an adaptation of Professor Pyg. The original character was created by Grant Morrison and Andy Kubert and first appeared in Batman #666.
- Lazlo Valentin was portrayed by Michael Cerveris. An unknown actor portrayed Professor Pyg in the episode The Trial of Jim Gordon, in which the character made a cameo appearance during a dream sequence.
- 6 Appearances of Lazlo Valentin (Gotham)
- 2 Images featuring Lazlo Valentin (Gotham)
- 3 Quotations by or about Lazlo Valentin (Gotham)
- Character Gallery: Lazlo Valentin (Gotham)