Hybrids by far aren’t a rarity anymore. For years scientists have been researching on the mix of human and animal. A while ago the government had decided to recruit Hybrids to the military to take advantage of their animalistic traits in warfare. 
Obviously there is a lot of controversy about the topic with many people seeing Hybrids as lowly or alien. Keegan however doesn’t bother with such differences. He appreciates each of his teammates equally, not seeing the sense behind differentiating.