After the Meiji Restoration in 1868, many makers of iron helmets adapted their skills to modelling animals such as fish, reptiles, beetles, shellfish, dragons and other mythical creatures. The same techniques used in riveting curved pieces of metal together to form armour or a helmet were employed to create feathers and scales. The models thus formed are astonishingly flexible and can be moved into different positions.
The British Museum has a group of these objects including a dragon, a pheasant, a crab and a slithering snake as well as this crayfish and a carp. Most of the pieces were made by later members of the Myōchin family of armour component makers. This crayfish is signed Muneaki saku (‘made by Muneaki').