Your build doesn't show much of what I would like to see in this category, for instance, it doesn't really show that the alien came from space, and the details aren't exactly up to par. Sorry, my vote is going to have to go your opponent.
Funny concept, but I was hoping to see more of your building skills. Sorry, my vote goes to LEGO Ninja.
I know it's a minor detail, but an important one, you neglected to mention the correct category name in your entry "It Came From Outer Space".