What character was on the first children's lunchbox based on a TV show?

A lunch box, spelled lunchbox in almost all UK and US dictionaries, also referred to as a lunch pail or lunch kit, is used to store food to be taken anywhere.

1935, Geuder, Paeschke and Frey produced the first licensed character lunch box, Mickey Mouse. It was a lithographed oval tin, with a pull-out tray inside. It had no vacuum bottle, but did have a handle.

In 1950, Aladdin Industries created the first children's lunch box based on a television show, Hopalong Cassidy. The Hopalong Cassidy lunch kit, or "Hoppy," quickly became Aladdin’s cash cow. Debuting in time for back-to-school 1950, it would go on to sell 600,000 units in its first year alone, each at a modest $2.39 USD.

Hopalong Cassidy or Hop-along Cassidy is a fictional cowboy hero created in 1904 by the author Clarence E. Mulford, who wrote a series of popular short stories and many novels based on the character.