this seems to me like it's more of a study in lighting effects than a completed movie. the characters look good, but the animation is a little stiff and there is no background to establish the situation.
is he in the city? an underground parking garage? if so, how are there giant lizards around that no one else is worrying about? i understand that creating a bunch more art assets takes time and effort and that you already put a lot into this, so whatever, if you feel like it there is room for improvement.
also, the word "creature" in the title makes me think there is going to be several different types of creatures, otherwise you could just call it "lizard police".