The Calle Shell

You get this item in the Lucky Dip.1) There is no way to keep track of how many you have2), but if you collect 100 of these rare little buggers, The Watcher will show up as an Improbable Event the next time you're in the Jungle, wearing a thong and not much else.3)

You'll then have a 'Weirded Out' buff that, like the Joker buff, will add or subtract from your attack and defence, but it will change every round, with the modifier being x1.5 to x-1.5, and a duration of 10 to 20 rounds.4)

1)
Located in AceHigh during Season 1.
2)
Unless you count them as you get them, anyway.
3)
The Watcher will be wearing the thong, that is - not you.
4)
Verified. Seriously.