varmint
An obnoxious person or troublemaker.
You'd be but a fierce young hound indeed, if at your time of life you could help to hunt a wretched warmint, hunted as near death and dunghill as this poor wretched warmint is!
Where it comes from
Dialectal form of vermin, derived from Latin vermis (“worm”), c. 1530–1540s. Perhaps influenced by Latin vargus (“bandit, outlaw, scoundrel”), though the pronunciation in /ɑː(ɹ)/ is more likely due to the same lowering of /ɛr/ > /ar/ found in carve < Middle English kerven and starve < Middle English sterven. The final syllable is probably altered after -ment; compare parchment < Middle English parchemyn.
Adapted from the Wiktionary entry varmint (CC BY-SA 4.0).