Superman 22 (May/June 1942) has quite the disturbing cover, when one notices the blood pouring from the puppet theatre.
On a lighter note, the Prankster gets his first real outing against Superman in this book, in a story by Siegel and Dobrotka.
The Prankster enlists a bunch of mobsters to financially back his latest scheme, to copyright the English language. He gets the rights to do this, which are upheld by the courts, despite Superman’s efforts to prevent it.
The story spends most of its time on the results of this, as the Prankster gets rich forcing newspapers and other media to pay him for the right to publish. Other services fall by the wayside, while the Prankster only allows articles praising him to be published for free.
When the end comes, it happens quickly. The Prankster delays paying the mobsters back on their investment, intending to run off with all the profits. We see that the copyright agent has really been his prisoner all along, and an impostor gave him the copyright. The hoods turn on the Prankster, and Superman shows up to toss them all into prison.
The Prankster returns a year down the road, in the pages of Action Comics.