the mother of all
the mother of all (something)
The largest, most extreme, or ultimate example of a particular kind of thing. The word that follows "of" is usually plural. Wow, that is the mother of all sandwiches. It's a foot high!
the mother (or mother and father) of all —an extreme example or very large specimen of something. informal
2007 Michael Simkins Fatty Batter Our pet pug dog, little Oona, does the mother of all dumps on the flower bed.