This puzzle challenges you to cover up all squares on the board with your coil -- the tail of your movement.
Begin by placing your blob in a square of your choosing. Continue by clicking on a free square in any orthogonal direction -- the blob moves in that direction until it hits something, either the edge of the board, a blocked square, or your existing coil. Be careful not to hit a dead end! Ay, there's the rub. You will have to shuffle off and restart.