Logic Masters Deutschland e.V.

Normal Sudoku rules apply.

Green lines are German Whispers Lines: digits in consecutive cells along green lines have to differ by at least 5.

The Whispering Hydra is hiding somewhere in the grid! It has:

• A body, which consists of a 3x3 magic square containing all nine different digits exactly once (a magic square is a square for which the digits in its rows, columns and main diagonals add to the same number).
• four monstrous heads! Each head attaches via a neck (a string of orthogonnally adjacent cells) to one of the body’s cells. The digit in that body cell has to be both the lenght of the neck (counting the head cell) and also the same digit as the one in the head cell.

The four necks have to be four different lengths.

The necks and heads cannot touch each other or themselves orthogonally, nor can they touch the body orthogonally (except the cell to which they attach and that cell can be touched on only one side).

Neither the body, nor the necks and heads can pass through cells on a German Whisper’s Line.

Additionally, this is the Whispering Hydra, meaning:

• Among the eight cells sourrounding each head, at least three have to be on a German Whisper’s Line.
• The four strings of digits consisting each of the body cell, neck cell(s) and head cell of each head also follow the German Whisper’s Line rule.

If anyone's up for translating these rules in german, I'll gladly post them :).