The animals of the land suffered from a famine for many months.
We're starving! This isn't fair!
The sky gods began to assemble the feast in the sky for the birds to enjoy.
I'll deliver the message to your wife!
The tortoise heard about the feast in the sky, and made sure he wouldn't miss this opportunity, so he went to the birds and asked for their help. At first, the birds didn't want to help him because he was known for being sly and deceiving, but after much convincing, the birds lended the tortoise some feathers so he could fly with them to the sky feast.
Agh! That sly parrot lied to me!
Before entering the sky feast, the tortoise told the animals that his new name was "all of you" since there was a custom that everyone had to change their names when invited to a great feast. So before the animals relished in the food, the tortoise asked the sky god, "For whom have you prepared this feast?" and it replied "For all of you." Thus, with the new name "all of you" the tortoise ate almost all the food, leaving some scraps for the birds.
The birds were so angered at the tortoise that they took back the feathers they lent him and flew back home leaving him in the sky. The tortoise asked if anyone could deliver a message to his wife "to bring out all the soft things in the house and cover the compound" so he could jump down from the sky. Only the parrot agreed to deliver it, but with other intentions in mind.
When the parrot reached the Tortoise's home instead of telling his wife to bring out all the soft things , he told her to bring out all the hard things from their house. So, when the tortoise saw things laid out in the ground he jumped, crashing into the hard objects. The fall caused his shell to crack, but with the help of the medicine man in the village, he stuck back the tortoise's shell, which is why his shell is bumpy and rough.