When we think of sexual selection we usually think of 1) female choice and 2) male-male competition. However, if these were the only two phenomena present one wouldn’t expect to find such a high degree of male variation in nature. Alternative reproductive tactics can explain this variability and one example is the instance of male morphs. These “sneakers” or “satellite males” exist across several taxa and have evolved many tricks to pass on their genetic material without the risk of being the alpha male.
Cuttlefish sneakers make themselves look like females.
Green treefrog sneakers wait for the bigger male to call and when a female approaches the male jumps in.
The scarab beetle has two (in some cases three) male morphs with different horn sizes and reproductive tactics. The males with large horns guard the females they mate with and fight off other large males. The males with small horns sneak by and mate with females, but waste no energy in guarding her.
Feel free to comment with other examples.