The Largest Testicles in the World.

The Largest testicles in nature weigh 1,100 pounds each. 

while not the biggest species of whale in the world, the Right Whale has the (Dubious)  honor of being the animal with the largest testicles in the world, Each testicles weigh around 500kg (1100). However, they"re not only big in absolute size, the weight of the testicles is around 1% of their total body weight, which is relatively large compared to other species.