The top hat is an attire worn by Oswald Cobblepot.
Whilst under the influence of hallucinogenic drugs, Edward Nygma hallucinates Oswald Cobblepot following his presumed murder at Nygma's own hands. During one of the hallucinations, Cobblepot breaks into song whilst donning the top hat.
After being poisoned by Ivy Pepper, Bruce Wayne begins to hallucinate himself at a party attended by several Gothamites and acquaintances such as Jim Gordon, Barbara Kean, Lee Thompkins, Harvey Bullock, and most of all Oswald Cobblepot, who is seen donning the top hat.
In the ten years following Gotham rejoining the mainland, Oswald began wearing the top hat as part of his new outfit.
- "Heroes Rise: How the Riddler Got His Name" (hallucination)
- "A Dark Knight: A Beautiful Darkness" (hallucination)
- The top hat is a significant piece of attire worn by the Penguin across many mediums in the DC Universe.