Way to mess with Robin’s mind there, Superman.
Don Cameron, Ed Dobrotka and Stan Kaye give the Toyman his first appearance in this book, in World’s Finest 20 (Winter 1945).
The Toyman had last appeared a few months earlier in Action Comics, and returns to steal a wavelength detector that he sets to give him an advance warning if Superman is approaching him. He then uses explosive toy boats to disable ships and rob them.
The wavelength detector is more of a hassle for Superman than the toy boats, but eventually he prevails by travelling underground, while using his x-ray vision to track the Toyman.
The Toyman gets a bit of a break, a year in prison it seems, as he does not return till early 1947, in the pages of Superman.