Mister Whistler

Mister Whistler is a fictional criminal and a one-time antagonist featured in comic books published by DC Comics. He appeared in Adventure Comics #61 in April, 1941 in a story titled "The Runaway Dinosaurs". He was a foe of the Golden Age Hourman.

Biography
Mister Whistler, first name unknown, was a mob boss operating out of Cosmos City in the 1940s. He stole a collection of model dinosaurs and found a way to animate them, setting them loose throughout the city to run amok.

This affair brought him into conflict with the costumed hero known as Hourman who, along with his sidekicks, the Minute Men of America, managed to defeat Whitler and his cronies and restore everything back to normal.