His fur seemed to grow darker and his eyes gleamed with a diabolical light.

There was really an unearthly beauty about him.

If the change happened in the twilight all the Ingleside folk felt a certain terror of him.

At such times he was a fearsome beast and only Rilla defended him, asserting that he was "such a nice prowly cat." Certainly he prowled.
Dr.Jekyll loved new milk; Mr.Hyde would not touch milk and growled over his meat.

Dr.Jekyll came down the stairs so silently that no one could hear him.