For a project I'm working on, I came across Yankee in Oz (1972) by Ruth Plumly Thompson. In the story is a giant named Badmannah the Terrible. He, according to the Oz Wikia, "has a magic fishnet, with which he fishes for treasure and captives from the lands below," including the missing princess from Whackajammy. In the end, Badmannah was sunk in the Nonestic Ocean.
Now, a year prior, there was a book, The Knight of Swords (1971) by Michael Moorcock. It marked the first book in a trilogy about his fantasy hero, Corum. (The series was completed in 1972.) Throughout these books, a wading giant, later revealed to be Rhynn, brother of Kwll, and the donor of Corum's fantastic optical prosthesis, who wades through the ocean with a fishnet, searching for the thing he lost. He even, at one time, catches Jhary-a-Conel in his net.
While Moorcock published first, Thompson apparently completed her book in 1959. Are these similarities purely superficial, or is it likely that one was inspired by the other? Or quite possibly some proto-giant-with-a-fishnet?