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 Giant squid can grow to a tremendous size : recent estimates put the maximum size at 13 m for females and 10 m for males from caudal fin to the tip of the two long tentacles ( second only to the colossal squid at an estimated 14 m , one of the largest living organisms ) .