Just want to expand on why Blackout hates the Meta-Ridley:

Imagine a disgusting mixture of part human, part fly. [Kind of like when Bart had his head replaced with a fly's](http://img2.wikia.nocookie.net/__cb20140505010813/villains/images/f/fd/BartSimpson1.gif), and his body was controlled by a fly head. Disgusting right if it was less humor and more realistic. Well that's what Blackout see's with the Meta-Ridley. On top of it, he is prideful in his race. So it's not only an abomination, but an affront to his species.