As I was going through my images from earlier this summer from the butterfly garden at the Texas Discovery Gardens in Dallas, I noticed something I missed before. Initially I liked this image of a Tiger Longwing butterfly because of how it was perched "stilt legged" on this leaf.
Upon closer inspection, I noticed the proboscis looked "funny" and saw it was covered in sugar crystals! Given that this species of butterfly likes passion vines with deep, tubular flowers, it seems sensible that the proboscis would get a bit of sugar on it. In this case the nectar dried and the sugar crystals formed - in essence unintended rock candy!