Dennis the Menace, for one, is a fictional character created by Hank Ketcham in 1951. He is a mischievous and troublesome boy who often causes mayhem in his neighborhood. The crossword solutions for this term are BRAT (4 letters), IMP (3 letters), and PEST (4 letters). BRAT is a slang term used to describe an ill-mannered child who behaves badly. IMP is a synonym for a mischievous or naughty child. PEST is another word for someone who is annoying or bothersome.