Crayfish or a small lobster.
This is small 4inches long 1.5inches wide and just under an inch deep.
This mould has no splits or holes, in very good condition, however I feel later than the other copper moulds I have for sale and not as sharp a moulding, but still a very nice mould.
Stamped with a mark -
This stands for the Army and Navy Co-operative stores
see - https://www.housefraserarchive.ac.uk/image/?id=HOFI00057
Late Victorian or Edwardian, these were sold in large sets so you could create spectacular displays.