|Appears in:||The Siege, The Outcast, The Golden Tree, Exile|
Slynella is a female flying snake of the forest kingdom of Ambala. As a member of her species, she has the capability to produce deadly poison and beneficial healing properties. She resides in Ambala with Mist, Stingyll (another flying snake) and two bald eagles, Zan and Streak.
After the chaw of chaws infiltrated and escaped from St. Aegolius Academy for Orphaned Owls, they rested in Ambala so they could tend to Soren, who had been wounded. Eventually, it seemed that he would die and an owl named Hortense flew off, thinking he couldn't do anything else. He eventually came to see Mist and she sent her, the eagles, and Slynella back to the sycamore tree that the chaw of chaws resided in. Upon arriving at the sycamore tree, Slynella was able to administer her life-saving antidote to Soren. Later, she sided with the Guardians against the Pure Ones during the siege on the Great Ga'Hoole Tree. Her arrival inevitably forced the Pure Ones into retreat, which won the battle for the Guardians.
Slynella, along with Stingyll, found Nyroc, the son of the leaders of the Pure Ones Kludd and Nyra, who had fled. At first, he mistakened the two snakes working for the Pure Ones, but they assured him they were on his side and Mist wants to see him. While Nyroc was temporarily in their care, Slynella and Stingyll used sky writing in order to help the owl read and write and choose his own name. When Nyroc reversed the alphabet in his name, the two snakes spelled out his new name: Coryn. After Coryn left for the Beyond, the two snakes greeted him with a Glauxspeed Coryn in their sky writing.
Doc Finebeak and Soren went to Ambala to get Slynella and Stingyll in helping their friend, Twilight. Although there was no guarantee that he would live, Twilight was in good health after three days from the snakes' treatment.
During the book burning of the Blue Brigade, Mist and her company provided refuge for the band. Slynella and Stingyll were shocked that the burning was ordered by King Coryn himself (who was for now under the spell of the Striga) and how dumb he had become.