As far as I know, Steinbeck's body of work doesn't include a horror novel in the typical definition of the genre. His writing style was more inclined towards depicting the harsh realities of life, poverty, and the human spirit. He was more into realism and social commentary rather than horror. For example, in 'The Grapes of Wrath', he shows the plight of migrant workers, not elements of horror.
John Steinbeck isn't really known for horror novels. He is famous for novels like 'The Grapes of Wrath' and 'Of Mice and Men' which are more about social realism, the struggles of the working class, and human relationships. So, if you're looking for a horror novel specifically by him, you might be disappointed as he didn't really write in that genre.
Yes, John Steinbeck is mainly known for his works in other genres like realism, but he has some elements in his writing that could be considered on the darker side. However, he is not typically associated with pure horror novels in the traditional sense like Stephen King. His works often focus on the human condition, and while there may be some disturbing or 'horror - like' moments in his stories, it's not his main genre.