This is a Buck Rogers XZ-44 Liquid Helium Toy Water Pistol manufactured by Daisy Manufacturing Co. in 1936. Inside the toy's metal body, where the red and yellow lightning bolts meet, a leather sack held the water for this water gun. The gun was also issued in a solid copper-colored finish, which has become the more rare of the two versions.
Paige: I like the idea of our little creature, Fitz, having a weapon to compensate for his lack of ability to fight. And it would be comedic to see such a cute harmless creature take on a weapon like that.