On sale date from the Catalog of Copyright Entries, Periodicals, 1948. The copyright record gives an incorrect cover date of "Summer". Both the indicia and the cover say "July".
Plastic Man [Patrick "Eel" O'Brian]; Woozy Winks; Lorraine Miller (introduction); Riverman (villain, introduction)
Synopsis
Plas must face the Riverman, a horrible freak who sported fins, claws and webbed feet, who made the river his home, and who was the last of his kind: humans born with gills and banished to the deep.