An entire packet of skittles.
The acidic juice instantly drained from it, disintegrating my vocal cords and leaving a solid rock of sugary crap balancing on munchy limbo. I managed to cough up the rock before it stretched my throat to the size of a duffle bag (length wise, naturally.)
The acid took a while to get over though. The sugar and whatever other additives must have been sticking to the sides of my throat, and the way that it was burning.. I'm surprised I don't have holes through my throat.