Keebler mascot (3)
I believe the answer is:
elf
'keebler mascot' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for elf that I've seen before include "spirit" , "Diminutive folklore creature" , "Santa's helper" , "He causes mischief" , "Mischief-maker" .)