I've heard here and there and on several occasions, mentions of Jujus. Hmm... but what are they? Some clues:
Juju Shoo-Shoo Powder: alpha.glitch.com/items/468/
'Something wrong' page: 'Perhaps the bad Jujus have [something something something - I can't remember exactly what it says on that page]'
There's even a quick glance of one in the encyclopaedia: alpha.glitch.com/items/441/
Juju Boss?: alpha.glitch.com/items/444/
They must be something bad/pesky, perhaps they're persistent and keep coming back... preventing gameplay? I guess there's only one way to find out: wait and see. Or a second way would be for a dev to answer :3