Just found this. Very interesting. From this site, some good stuff in here.
In 1555 Olaus Magus wrote a book called Historia de Gentibus Septentrionalibus in which he describes a monstrous fish as follows, “Their forms are horrible, their heads square, all set with prickles, and they have long sharp horns round about like a tree rooted up by the roots: They are ten or twelve cubits long, very black, with huge eyes Ö. the Apple of the Eye is of one cubit, and is red and fiery coloured, which in the dark night appears to Fisher-men afar off under waters, as a burning fire, having hairs like goose feathers” (Ellis 1994, 124). De Montford says its “huge protruding eyes actually seemed to flash fire” (Ibid, 265). The giant squid has the largest eyes of any animal. One observer said it skin was “brilliant carmine red” (Ibid, 129).
In 1632 a sea monster was said to have seven tails with eyes (Ibid, 126).
In 1673 another sea monster is described as having two heads and ten horns.
An 1845 description says there was “boiling of the water on both sides of it” and moved like a snake (Ibid., 366-7).