The initial idioms of the letter B

be as pleased as Punch	be as poor as church mice
be as pure as the driven snow	be as quiet as a mouse
be as regular as clockwork	be as right as rain
be as sharp as a tack	be as sick as a dog
be as sick as a parrot	be as silent as the grave
be as slippery as an eel	be as snug as a bug in a rug
be as sober as a judge	be as solid as a rock
be as sound as a bell	be as sound as a dollar
be as stiff as a board	be as straight as a die
be as stiff as a ramrod	be as strong as an ox
be as stubborn as a mule	be as thick as thieves
be as thick as two short planks	be as thin as a rake
be as thin as a stick	be as tough as old boots
be as ugly as sin	be as white as a sheet
be as white as snow	be asking for trouble