The giant squid

The giant squid is a deep-ocean dwelling squid in the family Architeuthidae, represented by as many as eight species. Giant squid can grow to a tremendous size: recent estimates put the maximum size at 13 metres (43 ft) for females and 10 metres (33 ft) for males from caudal fin to the tip of the two long tentacles (second only to the colossal squid at an estimated 14 metres (46 ft), one of the largest living organisms). The mantle is about 2 metres (6.6 ft) long (more for females, less for males), and the length of the squid excluding its tentacles is about 5 metres (16 ft). There have been claims reported of specimens of up to 20 metres (66 ft), but no animals of such size have been scientifically documented.

More info: en.wikipedia.org