The most difficult to obtain Juju is the Sacred Scull juju.
During the first weeks of the Adventure Trading Company activity, guests could get a Sacred Skull by simply trading “one of theirs for one of yours.” All you needed to do was find something in the park that could be fashioned into the shape of a skull (antenna balls, wadded napkins, and the remains of things executed by feral cats were popular) and trade it at the Company for a Sacred Skull juju (after paying the usual “exchange fee,” of course).
This stopped when significant complaints started. It turns out that even though Disney was using only the highest quality, organic, free-range, locally sourced, hand-painted, artisanally shrunken skulls, certain people have an aversion to using human skulls for any purpose they see as “frivolous” or “blasphemous.”
That is why today the Sacred Skull juju is no longer available in the park, is illegal to bring across state lines, and can be found on eBay selling for upwards of $1,000.