Short answers, pulled from the story.
Masahiro Ito designed the character Pyramid Head for the Silent Hill 2 video game. He rejected his initial sketch of a masked human and drew a creature with a pyramid-shaped helmet instead.
A German World War II tank enthusiast inspired Masahiro Ito by the lower hull of the King Tiger heavy tank. The sharp right and acute angles of the triangle suggest the possibility of pain according to the designer.
Pyramid Head appears in the 2006 film adaptation of Silent Hill as Red Pyramid portrayed by Roberto Campanella. He also makes an appearance in the 2012 film Silent Hill: Revelation once more portrayed by Roberto Campanella.
Pyramid Head functions as an executioner of Maria who is a delusion of James that strongly resembles Mary. His appearance reminds James of Mary's death and causes him to experience guilt and suffering regarding her three-year-long illness.
Roberto Campanella wore boots with a hidden sole which made him just under seven feet tall during filming. He also wore a five-part prosthetic which took two-and-a-half to three hours to apply for the role.