Exemple:
The shepherds had their dogs with them at night to help protect their sheep from the lone wolf that had been terrorising the village for the previous month. 
Santiago Atienza [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
Licence photo:
CC: Attribution, Commercial Use
Regionalism:
Neutral
Regional variant:
Neutral
Full Expression:
The “ull” Sound (/ʊ/): wolf
a fierce, four legged animal similar to a dog that lives in forests and hunts other animals