When you think of ancient, blood-sucking creatures, your mind might jump to bats, leeches, ticks, or mosquitoes. Maybe even creatures of lore come to mind, like vampires, the chupacabra, or kappa. But in the waters of Iowa's Mississippi River, a fascinating eel-like predator thrives. Dubbed a “living fossil” that hasn’t changed for millennia. This jawless fish is as ancient as it is unique.