I came upon this dark nebula while working on a mosaic of Cygnus. It sure resembles a shark.

B 145 – September 15, 2007
Constellation: Cygnus
Location: Godin/Newton Observatory, Pearson College.
Optics: Borg 77EDII at f/4.3
Camera: Canon 20Da on Kenko SkyMemo.
Exposures: 57 light frames of 90 sec, ISO 800. 1 hr 25 min.
Process: Calibrated with 35 dark frames and 25 flat frames in ImagesPlus. Combined using MinMax Excluded. Colour balance in Photoshop.