You are almost right :). The French translation of giant squid is not exactly "Calamar géant" but "Calmar géant" . A "Calamar" remains a squid but from a "cooking book" point of viewSeems giant squid translates directly. You are not the only one who would like for him to show us photos of le calamar geant!
I've read many books from Cousteau and one about cephalopods which translation may approximatively be "Octopus: the end of a misunderstanding" telling about how some famous writers in the french culture such as Jules Verne and Victor Hugo have contributed to describe octopus as a monster and how in reality the monster is shy, graceful and "intelligent". An interesting book apparently from 1973 even if, as octopus specialists you will probably learn nothing more than in TV documentaries.
Apart from that, in the french language, we have two terms for describing octopus: "Poulpe" and "Pieuvre". These terms are synonyms according to a dictionnary but in common language, some people say a "Pieuvre" is a giant octopus and "Poulpe" is the common size you see in your aquarium or by scuba/diving. Scuba divers and marine biologists prefer the use of "Poulpe".