Folklore
Animals were popular motifs in folklore across the ancient world. From India to the Mediterranean, storytellers used animals to map out human behavior and morality, teach lessons, or ground their society in patterns from the natural world. While the most famous animal folktales in the West are Aesop's fables from Ancient Greece, Iran had its own traditions, often with roots in Indian folkore.
Kalilah wa Dimnah is the story of two jackals, Kalilah (Ka-LEEL-A) and Dimnah, one of whom uses all his cunning to vie for power at the court of the lion king Pingalaka. Originally from India, the story was translated into Middle Persian in the Sasanian period and attributed to a traveling doctor named Burzōē. The Middle Persian edition, in turn, served as the base for a Syriac version and then an Arabic version by the prolific translator Ibn al-Muqaffa (d. 756/9). Today, only the Syriac and Arabic versions survive to reconstruct Burzōē's work, but the story remains, structured as a series of arguments and fables linked to Dimnah's quest for power. You can read an excerpt of the story here in which Kalila tells Dimnah a fable about the dangers of greed and ambition.
The second story, Draxt i Asurig, or The Assyrian Tree (sometimes known as The Goat and the Assyrian Tree) is a debate between a goat and a date palm about which one is more useful. Originally composed in Parthian and passed down by speakers of Middle Persian, the debate is part of a long history of dialogue literature from Near Eastern societies.
While Kalilah wa Dimnah uses animals to illustrate moral lessons, The Assyrian Tree describes the relationship between the natural world and human society. Both the goat and the tree compete to see which one is more useful to humans - even if it means that they aren't alive to see it. Even in death, they help further the Zoroastrian cosmic order by helping humans be more efficient in work, trade, warfare, and daily life. The full text of Draxt i Asurig can be found here.