The Loreley's Grasp (Spanish: Las Garras de Lorelei, lit. 'The Claws of Lorelei') is a 1973 Spanish horror film written and directed by Amando de Ossorio, and starring Tony Kendall, and Helga Liné. The film centers on a series of horrific murders in a German town by the Rhine river perpetrated by a deadly water spirit known as the Lorelei.

The film was released in theaters in the United States under the title The Swinging Monster on August 24, 1976, but most famously a few years later under the title When the Screaming Stops. It was later released on VHS in 1985 under the latter title before being released on DVD in 2007 under the original English export title. Critical reception for the film has been mostly negative, with criticism directed towards the film's script, and phony monster costume.