Wild man

He had rescued the duchess from the very fangs of the monster, which, he assured the ladies, was neither a wolf, nor a bear, nor yet a wild man of the woods.

"So said Hair-Face, and they killed him, because, they said, he was a wild man and wanted to go back and live in a tree."

[H]e was a sinner, unregenerated, a wild man in her estimation, a being of quite another kind than herself.

"David and I are very enthusiastic people, and we want to be able to make lots of noise. . . . David is quite a wild man when he gets excited with music."

He's a wild man, with all kinds of punches,—a whirlwind,— and he gets his man in the first rounds.

In no time, she has persuaded him to unleash his inner wild man, and soon they are washing down pills with booze and bouncing off the walls.

"They're saying I'm a wild man. If I turn the trick, they'll say I'm a genius." So said Royal Little, the mild, 50-year-old president of Textron Inc., whose unconventional production ideas have built a textile empire in less than three years.

In popular lore, Feynman often comes off as the wild man of physics, throwing out one crazy idea after another in a frenzied search for truth.