Spot the Frippet: scallywag.

Richmal Crompton's William Brown (and Mr Moss).

A scallywag is someone who takes delight in non-malicious naughtiness: a scamp.

(There have been different, historical, sorts of scallywag: firstly, a white southerner in America after the civil war who made profit from the cause of Black emancipation; and, secondly, a union agitator. But those meanings are out-of-date.)

A scallywag nowadays will probably be a small boy, though just possibly a man, who relies upon charm to get himself out of trouble. 

It'll usually work, too.

Scallywags are to be found wherever there are men, young people or young dogs, and on the whole resistance is useless.

So we might as well enjoy them.

Spot the Frippet: scallywag. This word started off meaning an undersized animal, and the transition from badly-going farm animal to useless person seems natural enough. Where the word came from before that is uncertain. It may be from the Shetland island of Scalloway, famous for its small ponies; or from the Scots scurryvaig, which comes from the Latin scurra vagas and means wandering fool.

You can spell this word scalawag if you like (it's still pronounced the same way) but it may mislead people into thinking you're talking about someone who's amusingly sarcastic about opera.