A living sea mine in the form of a mechanical pufferfish/blowfish. Could also be a huge pufferfish/blowfish that swallowed a sea mine for a more whimsical theme.
Pufferfish:
Sea mine:
Pufferfish that ate a sea mine/mechanical pufferfish:
The more I think about it, the better I like the idea of a real pufferfish eating a sea mine! 
Could add an eyepatch too for style points.
Art presented is not my own and merely used as a concept
