The phrase "a varmint" is correct and usable in written English.
It is typically used in informal contexts to refer to a troublesome or mischievous animal, often in a humorous or colloquial manner.
Example: "The raccoon has been rummaging through our trash again; that little varmint is getting bolder every night."
Alternatives: "a pest" or "a nuisance".
FrontierVille, however, has been sliding faster than a pioneer bitten by a varmint.
What if Nugent had called Ann Romney a varmint or brain-dead?
The cognoscenti was meanwhile perturbed that the fact that Palin seemed scared by her weapon, a small gun described by Chuck Snr as a "varmint rifle".
Mr. Benenson wrote about the.22-caliber Hornet, a varmint rifle developed by woodchuck-hunting experimentalists in Springfield, Mass., in the 1930's.
My neighbors assured me there was only one sure way to control groundhogs, and that was with a varmint gun -- a.22-caliber rifle.
It is not rare for Republican political figures to play down their suspected liberal tendencies witness Mitt Romney's memories of being a varmint hunter.
We had been on the lookout for a rapacious varmint; the day before, something had breached my garden's stalwart defenses — a five-foot cedar post and wire fence erected to deter rabbits and deer, augmented by 18 inches of chicken wire buried along the perimeter to thwart burrowing types.
We kicked over the most important stories of the week, including the announcement of pricing data and release dates for Apple's Watch, Box's earnings which caused the company's stock to move dramatically, and Meerkat, which I'm told is actually a small varmint.
Hey, maybe Olly isn't a demon varmint on "Game of Thrones".
A high-end.44 Magnum pistol will produce about 1,000 ft/lb of muzzle energy; a traditional "varmint" caliber, the.223, will produce about 50% more energy, and high-end rifles produce over 10,000 ft/lb!
In the process, returning wolves have become more than just an unwelcome varmint.
