Enemy of my Enemy is my friend

This is a quick painting about 4 hours or less. I've not done to many sci-fi images so here ya go.
The painting is basically about one alien force joining forces with humans to defeat another Alien enemy. There are so many films and books based upon aliens invading earth and trying to wipe us out would be cool if we were invaded by Aliens who want to protect us. Sounds a bit like Transforner I know.