Ultimate Skrulls
An ancient (and possibly oldest) alien empire that spans vast galaxies. They are a shape shifting race, that must consume the DNA of whatever they wish to emulate. They have a hive like mind and act as benefactors to other races they encounter, though they usually have motives of conquest and enslavement and believe themselves to be the universes "immune system" .
Their infrastructure is very strong, but their vast colonies have spread their forces thin and they are fighting many wars on many fronts.
