The term CUTTLEFISH RELATIVE can be solved by two crossword solutions: OCTOPUS (7 letters) and SQUID (5 letters). Both octopuses and squids are cephalopods, a type of mollusk that includes cuttlefish. Octopuses have eight arms and no internal shell, while squids have eight arms and two tentacles and an internal shell. Cuttlefish are related to both octopuses and squids, and all three species share many physical characteristics, such as their ink sacs and ability to change color.