Its that simple. Why are all creatures seemingly all bound to be around the same size. All quadrapedal creatures seem to be the same height and length, same for all the birds as well as the bipeds. I'd love to see more fluctuation in these sizes. Large, dinosaur like creatures wandering about would be cool, so would bird sized creatures running around as well. Giant creatures don't need to be insanely powerful or anything, they might have more health and damage, but they're also massive, easy to hit and easy to avoid, a smaller creature with the same stats would be much more dangerous. Bringing down these behemoths should yeld multiple meat and leather drops, making them valuable to hunt. Also, I can't be the only one finding the whole 3 surface creatures with like 4 birds and a handful of underground creatures that are all really the same running about. Scaling some of these creatures up, or down, would make exploration much more exciting! Landing and finding out that your planet has massive T-rex sized aliens running around would be awesome! Needing to hide behind cover, hunt from caves, or be a bada** and taking it out with a melee weapon would add a touch of variation the game needs so much. Scaled up creatures don't seem impossible, many miniboss' seem to be nothing more than this.
Yes. Especially if they make enemies that damage on attack rather than contact. A careful jump could let you ride that giant bird up into the sky.