What is the participial of sentence mailman backed away from lunging dog?

The participial phrase of the sentence "The mailman backed away from the lunging dog" is "backing away from the lunging dog".

Here's the breakdown:

* "backing away" is the present participle of the verb "to back"

* "lunging" is the present participle of the verb "to lunge"

Together, they form a participial phrase that describes the action of the mailman.