cold frog 

Someone who feels the cold more than others

I get lots of action in the winter because my girlfriends such a cold frog

cold frog by stone ager May 26, 2016

Cold as a frog's tail 

Equivalent to "Cold as a witch's titty in a brass bra." It comes from the idea that frog's don't have tails because they froze off.

"You better put on a coat", said my Southern Grandmother, "It's cold as a frog's tail out there."

Cold as a frog's tail by ChristopherBelt January 1, 2018