In European bestiaries and legends, a basilisk (/ˈbæsɪlɪsk/ or /ˈbæzɪlɪsk/, from the Greek βασιλίσκος basilískos, "little king"; Latin regulus) is a legendary reptile reputed to be a serpent king who can cause death with a single glance. According to the Naturalis Historia of Pliny the Elder, the basilisk of Cyrene is a small snake, "being not more than twelve fingers in length", that is so venomous, it leaves a wide trail of deadly venom in its wake, and its gaze is likewise lethal. Its weakness is the odor of the weasel, which, according to Pliny, was thrown into the basilisk's hole, recognizable because some of the surrounding shrubs and grass had been scorched by its presence. It is possible that the legend of the basilisk and its association with the weasel in Europe was inspired by accounts of certain species of Asiatic snakes (such as the king cobra) and their natural predator, the mongoose.
Chroma key compositing, or chroma keying, is a special effects / post-production technique for compositing (layering) two images or video streams together based on color hues (chroma range). The technique has been used heavily in many fields to remove a background from the subject of a photo or video – particularly the newscasting, motion picture and videogame industries. A color range in the foreground footage is made transparent, allowing separately filmed background footage or a static image to be inserted into the scene. The chroma keying technique is commonly used in video production and post-production. This technique is also referred to as color keying, colour-separation overlay (CSO; primarily by the BBC), or by various terms for specific color-related variants such as green screen, and blue screen – chroma keying can be done with backgrounds of any color that are uniform and distinct, but green and blue backgrounds are more commonly used because they differ most distinctly in hue from most human skin colors. No part of the subject being filmed or photographed may duplicate the color used as the backing.