RichThesaurus
before you can say Jack Robinson
vs
in two shakes (of a lamb's tail)
before you can say Jack Robinson
phrase
Very quickly; quicker than one expects.
in two shakes (of a lamb's tail)
How often have the words
before you can say Jack Robinson
and
in two shakes (of a lamb's tail)
occurred in a corpus of books?
(source:
Google Ngram Viewer
)