William Hope Hodgson
William Hope Hodgson was a great weird writer of the early 20th Century. He was loved by H.P. Lovecraft and Clark Ashton Smith, and China Mieville has often mentioned his named as an influence.
He's also a great creator of giant monsters. Books like "The House on the Borderland" and "The Night Lands" were filled with giant, mystical monsters.
Recently, I've been reading his work, collected by Night Shade Books in a continuing series. In the first volume, there is a series of stories about the Sargasso Sea. I was surprised to find out that the Sargasso Sea is an actual place. It exists in the mid-Atlantic and is filled with seaweed. The Bermuda Triangle is within its borders.
Each of Hodgson's stories I've read so far have included a giant animal. I suspect most of the other stories in the series do as well.
Anyone who is interested in giant monsters couldn't go wrong picking up Hodgson's work. It's great weird fiction anyway. And Hodgson most likely had a direct effect on some of my favorite giant monster movies. His story "The Voice in the Night" was the direct inspiration for Ishiro Honda's film Matango, better known as "Attack of the Mushroom People." It's a great little horror film. I'd be curious to learn if Hodgson was regularly translated into Japanese.
Here's a site about Hodgson (edit: web site is gone) and there seems to be plenty more if you're so inclined. I also think his work is in the public domain, so you can find much of it online. Here's "From the Tideless Sea" (edit: link also gone, here's what Gutenberg has), the first of his Sargasso Sea stories. Enjoy.