dung beetles
...these would be the beetles of choice.
Onthophagus taurus dung beetles,
showing size and horn variation among males.
Dung beetles in the widespread genus Onthophagus sport a bewildering array of horns. Not only do the horns of different species vary in shape, size, and the body part from which they grow, many species show a marked dimorphism within the males.
Consider these two male morphs of O. nigriventris, an African species:
The big guy on the right is a major male, and he does pretty much what you'd expect. He bullies his way around with shows of bravado, guarding his burrows…