More on Merry as a Cricket from Infoplease:

• Merry as a Cricket - Merry as a Cricket or as a Lark, or as a Grig. The French say, “Fou (or Folle) comme le ...
• William Shakespeare: Henry IV (Pt 1), Act II, Scene IV - Ned, prithee, come out of that fat room, and lend me thy hand to laugh a little.
• Dictionary of Phrase and Fable: M - Definitions, origins, and illustrative excerpts for words, phases, and literary allusions starting with "M"