What is the name of the Simpsons episode in which Marge calls a creature an "Oggly Boogaly"?

Sorry can’t help you…but Frank Zappa penned Great Googly Moogly way before Simpsons were even born.

The episode you are looking for is, The Bonfire of the Manatees. Season 17 – Episode 1. When Marge is inside a phone booth, there is a pounding on the glass. She turns around to see this. She screams out, “Aaah! An Oogly Boogly!” We pull back to see just how big it is.

Hopefully this is what you were looking for.