Here you go, a new Rancid for a new year.

I have come up with a name for his species. Rancid isn't actually a bat, he's an alien tentacle symbiote inhabiting a corpse, generally a bat. The alien species are called Sybientical, generally zipping along through space inside asteroids. When they land on a planet they seek out dead hosts to cohabitate with the body and blend in with the local fauna. This becomes difficult with sentient species, but they're quite benign. They don't have any of the host body's memories but they take on the core personality traits of their first host they inhabit and retain it from host to host.

Their only mission is to track down and destroy another species of virulent space parasites known as Parasendrils. They are red, vicious parasites that inhabit living hosts and destroy their personalities. They have a hive mind and their only goal is to completely devour all living creatures in the galaxy.

This is a plotline I've had in my head for a long time, so I'll probably start doing more with this.