RichThesaurus
happy as a clam
vs
happy as a pig in shit
happy as a clam
adj
Very happy and carefree.
happy as a pig in shit
adj
Extremely happy; obviously satisfied and carefree.
How often have the words
happy as a clam
and
happy as a pig in shit
occurred in a corpus of books?
(source:
Google Ngram Viewer
)