Squid's cousin (7)
I believe the answer is:
octopus
'squid's cousin' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for octopus that I've seen before include "one that's heavily armed?" , "Eight-legged creature" , "Marine creature" , "Tentacled marine mollusc" , "something from La Mer?" .)