Vamana Avatar: the dwarf

King Bali conquered the heavens and gave away everything he won. A small brahmana boy came to his sacrifice and asked for three steps of land. Bali laughed and promised — and the boy grew until two steps covered the earth and the sky.

For the third step Bali offered his own head, and by giving everything away he received more than he had lost. Children of five and up understand the ending better than adults do.