Printmaking

I think that in his description of the five Snark marks, Lewis Carrolls might have referred to some of his contemporaries. After listing the 5th mark “ambition”, Carroll devides Snarks into two types:

        It next will be right
            To describe each particular batch:
        Distinguishing
            those that have feathers, and bite,
            And those that have whiskers, and scratch.

This could be a reference to the Snark illustrator Henry Holiday and the engraver Joseph Swain, or generally to printmakers who make etchings and engravings. If that is such a riddle, keep in mind that the Snark is not necessarily a bad beast (as long as it didn’t turn into a Boojum).