The Scarlet King snake rarely gets over twenty inches in length while the Coral snake can grow to thirty inches or more. The bands of color are also different. The colors alternate red, yellow, black, yellow, on the Coral Snake and on the Scarlet King snake the colors are red, black, yellow, black. When I was a Boy Scout (fifty years ago) they taught us a little rhyme to help us tell the difference. It went:
Red to yellow
Kill a fellow.
Red to black
Venom lack.
In the photos below you can see a Coral snake that was killed by a laborer near Monterrey, Mexico where I was working in 1999. Below that there is a photo of one of the Scarlet King snakes that was killed today. The Scarlet King snake is a friend of man and a very beneficial little animal. The problem is that many people fear snakes so much that they usually kill them before they try to identify them. The poor little Scarlet King looks so much like his dangerous cousin the Coral, that in order to be on the safe side he usually gets the double "whammy"...OUCH!