She looked down, saw Oy looking up at her with his old fiendish grin, and that made her laugh harder than ever.

His yellow fangs were bared in a fiendish grin.

The man's lips showed a fiendish grin.

"In five minutes by that clock I'm going to kiss you," he said with a fiendish grin.

Fafhrd noted with a fiendish grin that the horse he knew best happened to be one of Hringorl's.

The bumbler was panting, but his old, amiably fiendish grin was gone.

And when he raises his head from his necessarily low perspective to look at the writer, he's wearing his old fiendish grin.

"Because," Pitt said with a fiendish grin, "I torched his yacht."

His face displayed a fiendish grin, as he waited in the darkness.

When he came in focus she could see his pockmarked face crack in a fiendish grin.