Gigantic Giant Squid (Oceans of the world): The largest squid on earth, Archituethis dux, is known to reach 60 feet in length. Squid attaining the length of 100 feet have been reported for ages, and the sucker marks and stray tentacles associated with sperm whales suggest squid of the amazing size of 200 or even 300 feet ! the largest proposed size was 900 feet from a crushed sterm whale wased ashore ! since the proportions of sucker size and tentacle size to body size in Architeuthis is constant, these estimates are flawless. However, squid of entirely unknown genera could be responsible for these sucker marks and tentacles, in which case their size isn't the mystery, but their existence.