In sculptures, Sedna is often depicted with the head and upper body of a woman and the tail of a marine mammal, similar to a mermaid.

She is called Sassuma Arnaa ('Mother of the Deep') in West Greenlandic and Nerrivik ('Table', Inuktun) or Nuliajuk (Kivalliq Region, Nunavut, Canada).

[3] In one legend Sedna is a giant, the daughter of the creator-god Anguta, with a great hunger that causes her to attack her parents.

[2] When she is angered, the angakkuq (shaman) travels to wash and comb her hair for her, after which she is placated and releases the animals to the hunters.

Other versions of the legend depict Sedna as a beautiful maiden who rejects marriage proposals from the hunters of her village.

When an unknown hunter appears, Sedna's father agrees to give her to him as wife in return for fish.

Sedna clings to the kayak but her father grabs a little ax and chops three of her fingers off before striking her on the head.

The stroke to her head sends Sedna to the ocean floor where she resides, commanding the animals of the sea.

[11] In each version she sinks to the bottom of the sea, worshipped by hunters who depend on her goodwill to supply food.

She is generally considered a vengeful goddess, and hunters must placate and pray to her to release the sea animals from the ocean depths for their hunt.

[12] At Killiniq, people threw worn-out harpoon-heads, broken knives, and morsels of meat and bone into the sea as offerings.

[2] 90377 Sedna, a trans-Neptunian object discovered by Michael Brown (Caltech), Chad Trujillo (Gemini Observatory) and David Rabinowitz (Yale University) on November 14, 2003, is named after her.