Jürgen Grasmück (* 23. Januar 1940 in Hanau, Hessen; † 7. August 2007 in Altenstadt) was a German author of Horror and Science Fiction books.
Dan Shocker is one of his numerous pseudonyms as:
Albert C. Bowles, Bert Floorman, J. A. Garett, J. A. Gorman, Jay Grams, Jürgen Grasse, J. A. Grouft, Jeff Hammon, Ron Kelly, Rolf Murat, Steve D. Rock, Owen L. Todd and Henri Vadim.
He is best known for the series of horror fiction stories Macabros and Larry Brent.