Now break them down into sub groups. For each group you should be able to have at least 2 sub groups. Record your reasoning for their distinctions. Your last grouping will be to distinguish between individuals. This is the most specific your group can be about describing these Beasties.
More detail is explained below.
Now, use normal naming conventions for order, genus and species. Develop a dichotomous key for your groups of Beasties. Now that you have names and a key you need to develop a branching tree that describes the relationship between each Beastie. It's based on your key and will resemble one of the two models shown below. You need to explain where they live, how they move, what they eat, etc.