The Daughter of Tuoni acts as a gatekeeper between the world of the living and the world of the dead.
She brings the dead with her boat to the island of Tuonela, Land of the dead.
Bring a boat, Tuoni’s daughter,
Bring a ferry-boat, O maiden,
That may bear me o’er this channel,
O’er this black and fatal river.
The shaman Väinämöinen manages to fool the Daughter of Death that he is dead and she lets him enter Tuonela. But once they realize he is still alive, they try to prevent him from leaving. The shaman must transform into a snake and swim across the river back to this world.