Elderberry Methuselah is a character only appearing in the Shrek comics.
Role in the comics
After Shrek is refused entrance to the Crunchypants Cereal Factory, Elderberry asks him for directions to said factory. Despite being "too old and senile", he's still hired as the sogginess inspector for the cereal companies. Shrek tells him that he looks okay for the job, and agrees to guide him to the factory. Unfortunately Shrek's giant hand accidentally knocks him out. While he felt bad for the man, he decides to steal his clothes in order to disguise himself as the sogginess inspector. That way he can pass security and save Donkey.