The Hammer Coral is a large polyp stony (LPS) coral and often referred to as Euphyllia Hammer Coral or Anchor Coral. Its common names are derived from the appearance of its hammer-, or anchor-shaped tentacles. Its polyps are visible throughout the day and night and hide its skeletal base. It may be green, tan, or brown in color, with lime green or yellow tips on the ends of its tentacles that glow under actinic lighting. Some varieties may be branched which makes them look similar to a Torch Coral (E. glabrescens).