While researching local history in the town of Cockermouth, in Cumbria, England, I came across the coat of arms below on a gravestone. The gravestone is listed on the Find a Grave website here, and is dedicated to three members of the Brown family. This pamphlet, snappily entitled All the Monumental Inscriptions in the graveyards of Brigham and Bridekirk near Cockermouth in the county of Cumberland from 1666 to 1876, describes the arms as the "Arms of the Brown family" on page seven.
I have uncovered just one other reference to these arms, in the Middle Temple Bench Book. Page 232 lists a "Joseph Brown", whose family originates from Cumberland, and describes his arms as "Az., on a Chev. wavy or between three fleurs-de-lys arg. a thistle’s head ppr." This seems to match the arms on the grave below, but excludes the crest.
The crest, to me, looks like a snake entwined around a pigeon, and I haven't been able to find any other examples of a similar crest; although I may just be looking in the wrong place. Is this crest common in heraldry? What might the origin or heraldic description of this device be?
Suggestion that this may be a secretary bird which are often depicted with snakes; possible, but as far as I know the family did not have any connection to Africa - my furthest knowledge of the family is limited to the summary in the bench book; that they served Lord Dacre against the Scots in what I presume would be the 1500s, around the Battle of Flodden.