Not super funny, but pretty cool/weird stuff in a project I inherited:
app <- -> exports.setup = it
in LiveScript seems to compile to
(function(it){ return exports.setup = it; })(function(app){})
which is pretty crazy.
Another one, just above some code making many deep monkey-patches to the Sequilize db driver:
/* HOLY FUCK THIS IS THE SKETCHIEST THING EVER */
made me smile.