assailant

Someone who attacks or assails another violently, or criminally.

I’ll put myself in poor and mean attire, And with a kind of umber smirch my face; The like do you; so shall we pass along, And never stir assailants.

[…] commonly some of us used to get up a tree to look out for any assailant, or kidnapper, that might come upon us; for they sometimes took those opportunities of our parents absence to attack and carry off as many as they could seize.

A hostile critic or opponent.

1782, Frances Burney, Cecilia, London: T. Payne and Son and T. Cadell, Volume 5, Book 9, Chapter 3, p. 41, […] the assailants of the quill have their honour as much at heart as the assailants of the sword.

Assailing; attacking.

But he though blind of sight, / Despis'd, and thought extinguish'd quite, / With inward eyes illuminated, / His fiery virtue roused / From under ashes into sudden flame, / And as an evening dragon came, / Assailant on the perched roosts / And nests in order ranged / Of tame villatic fowl, but as an eagle / His cloudless thunder bolted on their heads.