It's cacti :D So I think getting it to feel dramatic is your challenge here. I would try some thumbnails first and see which works for dramatic purposes. A Dutch angle always seems to be more impressive. I tried some quick thumbnails, but they're not the best, but I hope it inspires you somehow. Also make sure you use the rule of thirds. So your moon is dead center. You could use it to frame one of the focal points, the hero or monster. Also Look at references of Iguanas fighting or something and maybe you can get a more dynamic pose for your creature, because it doesn't look very threatening at the moment :)
Great point about the thirds! It's not supposed to be a fight though. I invasioned the lizard to be more confused about why the tiny person would point at spear at them :)
Fantastic feedback, Jacque! :D Even tho the idea is not getting a fight scene, the thumbs you proposed are quite good :D
Ah ye, I was thinking it had to be all action and fighting! My bad :)
Perhaps you could try and push that idea more with the lizard, add like a raised brow, or have that come across through the pose, like maybe even have them laying down, legs crossed, like bored, and have them looking with their head tilted down toward the person, not reering backward.