I'm not sure if we can do Feral Chimera guys. According to the wiki, they didn't exist till after the Chimeran war and we are still going through it.

It makes sense though because feral chimera only existed because Chimera had already won the war in the third game and because of the victory, it meant some Chimera went to do their own thing because there was no human superpower left. Since there was little human resistance or any need to be used by the Chimeran leaders, they started to reproduce in the wild.