cold fish (noun)

1. Her minimalist black dress and stone-cold expression gave her the appearance of a fashionable cold fish.

2. Despite his reputation as a cold fish, he surprised everyone with his grand romantic gesture of buying her a bouquet of red roses.

3. The ancient Greek sea god, Poseidon, was often depicted as a cold fish who controlled the seas with his aloofness and unemotional nature.

4. The character of Mr. Freeze in the Batman cartoons is portrayed as a cold fish with his icy demeanor and lack of emotions.