Science

• Polymorphonuclear leukocyte or granulocyte
  Granulocyte
  Granulocytes are a category of white blood cells characterized by the presence of granules in their cytoplasm. They are also called polymorphonuclear leukocytes because of the varying shapes of the nucleus, which is usually lobed into three segments...
  
  , a type of white blood cell
• Polymorph, a trade name for the low melting-temperature polymer, Polycaprolactone
  Polycaprolactone
  Polycaprolactone is a biodegradable polyester with a low melting point of around 60°C and a glass transition temperature of about −60°C. PCL is prepared by ring opening polymerization of ε-caprolactone using a catalyst such as stannous octoate. Recently a wide range of catalysts for the ring...
  
  
• Dreissena polymorpha, the species commonly known as the Zebra mussel
  Zebra mussel
  The zebra mussel, Dreissena polymorpha, is a small freshwater mussel. This species was originally native to the lakes of southeast Russia being first described in 1769 by a German zoologist Peter Simon Pallas in the Ural, Volga and Dnieper rivers. They are still found nearby, as Pontic and Caspian...
  
  
• One of several forms of crystal structure of a material displaying polymorphism (materials science)
  Polymorphism (materials science)
  Polymorphism in materials science is the ability of a solid material to exist in more than one form or crystal structure. Polymorphism can potentially be found in any crystalline material including polymers, minerals, and metals, and is related to allotropy, which refers to chemical elements...
  
  

Fiction

• Polymorph (novel)
  Polymorph (novel)
  Polymorph is a 1997 cyberpunk novel by American science fiction author Scott Westerfeld.-Plot:"Milica Raznakovic" is the principal alias employed by the protagonist, a shape-changer or "polymorph." Living in a recession-hit future New York, she spends her time partying anonymously, each night in a...
  
  , a 1997 novel by Scott Westerfeld
• "Polymorph" (Red Dwarf episode)
  Polymorph (Red Dwarf episode)
  "Polymorph" is the third episode of science fiction sitcom Red Dwarf Series III, and the fifteenth in the series run. It premiered on the British television channel BBC2 on 28 November 1989. It is considered by some to be the series' best. Written by Rob Grant and Doug Naylor, and directed by Ed...
  
  , an episode of the British science-fiction sitcom Red Dwarf
• A magical spell in many fantasy role-playing game
  Role-playing game
  A role-playing game is a game in which players assume the roles of characters in a fictional setting. Players take responsibility for acting out these roles within a narrative, either through literal acting, or through a process of structured decision-making or character development...
  
  s that transforms a target into a different creature for a period of time