Wiktionary
mother of all
phr. (context colloquial English) Used before a plural noun to form a compound noun having the sensethe greatest or largest of its kind.
Usage examples of "mother of all".
Here, also, every young girl within the Temple was sent to render service in her turn (for all women owed service to the Mother of All Men).
According to Norfressan theology, Kontifrio was Orr's second creation (after Orfressa, the rest of the universe), and she is the most nurturing of the gods and the mother of all Orr's children except Orfressa herself.
Theyd simply sweep the cockpit with stun blasts and hed wake up in a day or so, nursing the mother of all headaches.