Answer:Quickly eating the last cookie--participial phrase
Step-by-step explanation:
A participial phrase can be a present or past participle. When the participle is present, It ends in -ing and when it is a past participle will end in -ed,-en,-d, -t, -n, as the case may be. We can say that a A participial phrase will function as an adjective which describes a noun even though it looks like a verb in a sentence.
---Quickly eating the last cookie, Babs left the kitchen
----Quickly eating the last cookie = present participial phrase which describes the noun, Babs