Multi-Ouroboros is a variation on the Snake puzzle style that frequently shows up in WPCs. This particular realization is original to this blog to the best of my knowledge. The object is to shade in some squares which form a single closed loop that does not touch itself, even at a point. The loop is composed of a number of different snakes, each biting the tail of the next snake in line; specifically, the head of one snake is adjacent to the tail of the next one. The head of each snake in the loop is given as a shaded square with a number, and the number tells the total length of that snake. The other type of clue is an unshaded number, which tells how many of the eight surrounding squares are part of the whole loop. No snake can pass through a square with an unshaded number.
Below is an example puzzle and its only solution. The red lines show the snakes that make up the loop.
- Some snake heads will have question marks. The length of that snake must be deduced on your own.