Penguin's Umbrella

Penguin's Umbrella is no ordinary umbrella, having built-in weaponry such a gun or knife.

Arkham Origins Incident
In Penguin's office, there is a display case with several umbrellas and his top hat. Penguin used his umbrella to torture Alberto Falcone. Some of Penguin's Henchmen talk about why their boss carried an umbrella, and thought that it may be a gun, a sword, or have a poison tip. One henchman thought that when the umbrella was opened, it could hypnotize the victim when spun (an Easter Egg reference to Danny DeVito's Penguin from Batman Returns when he pretended to hypnotize Max Shreck).

Cold, Cold Heart Incident
Penguin's Umbrella was briefly seen with Penguin when Batman entered the Lobby at GothCorp to rescue Ferris Boyle from Mr. Freeze.

Arkham Origins Blackgate Incident
Penguin had a bribed guard rescue him and bring him his umbrella from the prisoner belongings lockup. Penguin then killed the guard with his umbrella but left without it.

Assault on Arkham Incident
When the Suicide Squad came to the Iceberg Lounge for help from Penguin to get into Arkham Asylum, Penguin spotted Harley Quinn, he took out his umbrella, (which had a gun built into it), pointed it at her, and explained to Deadshot and the rest of the Suicide Squad about how Harley and Joker had stolen a truck that was full of cigarettes and crashed it into the harbor "just for a laugh." Deadshot managed to dissuade Penguin from shooting Harley and Penguin gave him the documents to get into Arkham. Penguin then told the Squad that they could stay the night in the rooms above, and that he didn't want to see any of them on his turf again.

Arkham Asylum Incident
Batman could see a collection of Penguin's Umbrellas in a display case in the South Corridor at the Arkham Mansion.

Arkham City Incident
Penguin uses his umbrella to kill GCPD Officer Best, who was in his gang as an undercover spy. He also uses it to unleash a Titan-fueled inmate on Batman. After Batman defeats Penguin, an officer can be seen holding Penguin's Umbrella in the Iceberg Lounge.

Arkham Knight Incident
Penguin's Umbrella was seen in a display case for Penguin along with a top hat in the Evidence Room at the GCPD Lockup.

If the Batmobile gets destroyed on the Tim Burton's Batman-based race tracks, the hypnotizing spirals based on Penguin's umbrella appear briefly.