Katz started his career in the 1940’s as a “Golden Age” comic book artist working in the studios of C.C. Beck, Jerry Iger and Joe Simon and Jack Kirby.
By 1974 he began his proto-graphic novel, First Kingdom, a project lasting twelve years and comprising 768 pages.
The latter part of his life he was a drawing and anatomy instructor in the SF Bay Area. Here are examples from one of his sketch booklets. I picked this up from him at a comic convention back about 2019.