One folk tale that almost every Nigerian child knows is the story of the Tortoise and the birds. I'm a secondary school English teacher in Enugu now, but I first heard it from my grandmother when I was about six, sitting outside her house in the evening when the electricity was off.
In the story, the birds are invited to a great feast in the sky. The Tortoise, who's famous for being clever and greedy, desperately wants to go, but of course he can't fly. So he persuades each bird to lend him one feather, and they make him a pair of wings. Before they leave, he tells the birds that it's a custom for everyone to take a new name for the feast, and he chooses the name 'All of you'. When they arrive, the hosts bring out the food and say it's for all of you, so the Tortoise claims it's all for him and eats the best of everything, leaving the birds only scraps. The angry birds take back their feathers and fly home, leaving him stuck in the sky. He asks them to tell his wife to put soft things outside the house so he can jump down, but they tell her to put out hard things instead. He falls and his shell cracks into pieces, which is why tortoises have a patterned shell today.
I think the story teaches a couple of things. The obvious lesson is that greed and trickery eventually catch up with you. But I also like that it's about community. The birds trusted him and he broke that trust, and once that happens, nobody will help you. I tell it to my students, and they always love the ending.