A king had seven sons, and when the other six went off to find brides, he kept the youngest with him because he could not bear to be parted from them all. They were supposed to bring back a bride for him, as well, but they found a king with six daughters and wooed them, forgetting their brother. But when they returned, they passed too close to a giant's castle, and he turned them all, both princes and princesses, to stone in a fit of rage.
When they did not return, the king, their father tried to prevent their brother from following, but he went. On the way, he gave food to a starving raven, helped a salmon back into the river, and gave a starving wolf his horse to eat. The wolf let the prince ride on him, instead, and showed him the giant's castle, telling him to go inside. The prince was reluctant fearing the wrath of the giant, but the wolf consoled him. The wolf persuaded the prince to enter the castle for there he would encounter not the giant, but the princess the giant kept prisoner.
The princess was very beautiful and the prince wanted to know how he could kill the giant and set her and his family free. The princess said that there was no way, as the giant did not keep his heart in his body and therefore could not be killed. When the giant returned, the princess hid him and asked the giant where he kept his heart. He told her that it was under the door-sill. The prince and princess dug there the next day and found no heart. The princess strewed flowers over the doorsill, and when the giant returned, told him that it was because his heart lay there. The giant admitted it wasn't there and told her it was in the cupboard. It was not there, and she put garlands of flowers on the cupboard and told the giant it was because the heart was there. He told her that, in fact, a distant lake held an island with a church; the church had a well where a duck swam, and had an egg in it, and the egg held his heart.
The prince rode the wolf to the lake, and the wolf jumped over the lake. The prince called upon the raven, and it brought down the keys to the church. Once inside, he coaxed the duck to him, but it dropped the egg in the well first, and the prince called on the salmon to get him the egg. The wolf told him to squeeze the egg, and when he did, the giant screamed. The wolf told him to squeeze it again, and the giant promised anything if he would spare his life. The prince told him to change his brothers and their brides back to life, and the giant did so. Then the prince squeezed the egg in two and went home with his bride (the server of the giant) and his brothers and their brides, and the king rejoiced.
Baldur's Gate II: Throne of Bhaal also includes an evil giant who cannot be defeated until his heart is located and destroyed.