Menacing aspect

"Good evening, Widgeon," said Captain Bradbury. There was only one word, Freddie tells me, to describe the gallant C.'s aspect at this juncture. It was sinister. His eyebrows had met across the top of his nose, his chin was sticking out from ten to fourteen inches, and he stood there flexing the muscles of his arm, making the while a low sound like the rumbling of an only partially extinct volcano. The impression Freddie received was that at any moment molten lava might issue from the man's mouth, and he wasn't absolutely sure the liked the look of things.

(from Trouble Down at Tudsleigh, by Sir Pelham Wodehouse)