Canon 30D, handheld
One summer I found the largest caterpillar I'd ever come across, that of a cecropia moth (Hyalophora cecropia,) larger in diameter than my thumb and better than 100mm long. And not only that, but studded with colorful little war clubs of spiked protrusions – brutishly menacing, but flamboyantly so. I captured it to do some macro work in controlled conditions (in this case, meaning someplace I could maneuver around rather than the barely-accessible plant where I found it,) and during the session another unidentified caterpillar, perhaps 15mm in length, happened along. Blithely disregarding the Prime Directive, I moved the new one to the branch where the cecropia sat and it helpfully meandered right over the feet of the giant, then paused as if realizing something wasn't quite right. The scale shot is expressive all by itself.