Lauren LeFranc, showrunner of The Penguin, recently opened up about the show’s ending in an interview. LeFranc discussed key twists in the season finale, explaining Oz’s decision regarding his protégé,

For a few episodes, The Penguin played around with the idea Colin Farrell’s Oswald Cobb would be a sort of antihero. After all, he presented himself as a working man, willing to upset the status quo for the people of Crown Point.

The Penguin leaves no doubt that Oz is a monster, especially when he murders Vic in cold blood – and he sealed his fate with one line.