Giant squid is one of the oceanic cephalopods with weak swimming ability. Its funnel lock is simple and straight, its water spray ability is weak, its fins are small, and its stroke ability is not very good. Giant squid's head, carcass and wrist muscles have a higher concentration of ammonia ions, and the specific gravity of ammonia ions is slightly smaller than that of sea water, so it can obtain greater buoyancy. The pigment cells on the body surface of the Giant squid, especially the back, are very developed, and even the surface of the internal organs has dark red pigmentation. The expansion and contraction of pigment cells on the body surface makes the body color change rapidly, which becomes a protective adaptation of Giant squid.

Giant squid feeds on other cephalopods such as sail squid and squid, as well as small fish.
At the depths the Giant squid inhabits, the only light comes from the organism's own glow, often from bacteria carefully cultivated in light-emitting organs in order to obtain light. Unlike whales that live in the same water depth, Giant squid has huge eyes, so they are likely to use some of their visual functions when hunting.