This week, the question was: What is the little critter on these mint leaves?
This is an assassin bug nymph (juvenile). Assassin bugs are beneficial, predatory insects. They have stout piercing/sucking mouthparts that they use to insert into their prey, inject digestive enzymes, and then suck out the bodily fluids. Most assassin bugs actively search for prey, though some wait for prey to move within striking distance. Adults and nymphs primarily prey on caterpillars, beetle larvae, aphids, stink bugs, and flea beetles. For more information, see this page.