The Amalgam are a parasite phenomenon made up of four extremely powerful entities that scour the multiverse in order to bring about the destruction of every single universe in existence. The individual members of the Amalgam include The Herald, The Envoy, The Emissary to the End, and The End.
The Herald is sent first to scour the universe and destroy its resources, thereby weakening its defenses. He creates an aura of decay around him that spreads out from him and slowly destroys any resources; fuels become non-existent, food becomes scarce, and even water dries up. The Herald appears as a male member of the dominant species of whatever planet he is currently on, however his face fades in and out of a skull.
After The Herald has begun his work, The Envoy and Emissary are sent forth.
Those who die of starvation or dehydration or the like in his aura become The Emaciated, ravenous undead creatures that serve his will and protect him.
The Envoy destroys all flora and fauna. The Envoy is a hole in reality appearing alternatively as a literal hole or as a swirling mass of nothing.
The Emissary to the End
The Emissary slaughters the majority species on the planet and will specifically target any major threats that could possibly prevent The Amalgam from completing their mission. The Emissary appears as an arachnid like being composed of many parts of The Fears.
The End appears as a universe mirroring the victim universe until it can crack through, overtaking the universe and slowly begins to devour it.