Hear of the Gila monster? These lizards are the biggest in the US and possess venomous saliva. They also claim an unusual ability to eat as little as three big meals a year, while managing to keep their blood sugar stable. Back in the early 1990s, researchers discovered a component in the lizard’s venom that mimics the activity of a human hormone that stimulates insulin release when blood sugar levels rise. Exenatide, an injectable drug based on the toxin, helps people with diabetes maintain healthy glucose levels and even lose weight.