90 second animation project

Yesterday I was given the brief to my new project. I have to write a script and create an animatic it to put it simply. I'm going to use the script from my narrative project which is titled "It came from the planet Earth"

The premise of this script is as follows:

A spaceship is flying through space and rockets its way to a strange alien planet where on landing a human
astronaut goes to explore the planet with a scanning device. While roaming this planet he is noticed by an alien creature which is hungry and upon seeing the spaceman just roaming around the planet’s surface the creature decides to eat the astronaut to satisfy it's appetite. The Alien creature stalks the spaceman, trying to close the distance between the both of them. Soon as the creature makes his first attempt the capture the spaceman he is eaten by an alien tree which the spaceman fails to notice. Moments later the alien creature breaks free from the carnivorous tree and chases after the spaceman once more. Upon the alien creatures second attempt the alien creature makes sure nothing will get in his way again and when he's about to strike he gets capture by the spaceman with use of his bubble gun and taken back to the spaceman’s ship and then off planet. We then see that alien creature has been domesticated and is now the spaceman pet being fed a steak.

So far I have decided on a final design of my two character and I am currently working on the background.
Here's the concepts that I did including the final design

Spaceman:

 Final Design Choice

Alien Creature

Final Design Choice

I'll put the the designs of the world in another post not to make this to bloated.