Even the most well-endowed men have nothing on the tuberous bushcricket, or katydid, which UK biologists say holds the world record for the creature with the largest testicles—at least in relation to the weight of its body. At 14% of body weight, this would be equivalent, in human terms, to a 200-pound man sporting 28 pounds of male baggage, reports LiveScience. The previous record holders had been fruit flies, weighing in at 10.6% of body weight.
But it's not just for bragging rights: Scientists suggest the purpose of such massive cojones is to "allow males to capitalize on the readily available supply of willing females. They allow males to have a greater rate of ejaculate production rather than producing extra-large ejaculates." (More katydids stories.)