I recall something like this from Thomas Pynchon's Gravity's Rainbow:
Colder than a witch's tit,
Colder than a bucket of penguin shit,
Colder than a hair on a polar bear's ass
Colder than the frost on a champagne glass.
The possibilities are endless:
Colder than the frozen heart of a leftist who loves Humanity but hates his neighbor. (MavPhil original!)
Colder'n a fairy's fanny in Fargo in February. (MavPhil original!)
Colder'n a witch's tit in a cast-iron bra.
Colder'n a ticket taker's smile at the Ivar Theater on a Saturday night. (Tom Waits, Diamonds on My Windshield)
Cold enough to freeze the balls off a pool table.
Colder than moonlight on a tombstone.
Colder than a polar bear's PJs.
Cold enough to freeze the balls off a brass monkey.
There's 15 feet of snow in the East and its's colder'n a well digger's ass, colder'n a well digger's ass . . . . (Tom Waits)