According to the Japanese folklore, tsunakiri ika are large, squid-like creatures with round bodies and wide wingspans. They have two crab-like, segmented arms ending in hooked talons, and enormous, round eyes. Tsunakiri ika live in northern waters, although they occasionally are found as far south as Hiroshima Prefecture. As their name suggests, tsunakiri ika use their sharp beaks and claws to cut the ropes hanging off of ships — particularly anchor lines. They are disliked by sailors and fishermen for this reason.

Tsunakiri ika is described in Chikuzen bakemono emaki, a yōkai picture scroll by an anonymous author.

In the third year of Bunsei (1820), the author of Chikuzen bakemono emaki visited the home of a fisherman named Yōshichi in Nokonoshima (present-day Nishi Ward, Fukuoka City). The head of a round, squid-like creature about half a tatami mat in size was hanging on the wall. Yōshichi explained that some time before, while he was hauling rice for the lord of Higo to the capital, he saw it in the open waters off of Tomo, Bingo Province (present day Fukuyama City, Hiroshima Prefecture). It looked like it was suffering and near death, bobbing up and down on the surface, and he somehow managed to catch it. Yōshichi showed a drawing of the creature and explained that it was called a tsunakiri ika, commonly found in the northern provinces. Boatmen detest them, as their anchors are frequently cut and lost by these creatures. From beak to tail they measure two shaku eight sun (about 1.06 m), and their wingspan measures one jō one shaku three sun (about 4.28 m).