These: http://www.thelovecraftsman.com/2011/04/hp-lovecraft-russian-nesting-dolls.html

I'm desperately trying to find a way to buy a set

I'd use Cthulhu dolls as a monster cup. Im using some white plastic bag at the moment. Would be very,very nice of FFG if they would put some monster cup in the MIskatonic Horror(a bag or some bowl)