Pick a subordinate category that you think fits your creature best
Continue until you arrive to the Species category as seen here, keep in mind that Animalia is a Kingdom and the order goes from bottom and upward in the image.
Take your creature's name and Latin-ify it to your liking. Else you can use a translator and pick a word and translate it to Latin, then put it at the end of your creature's Taxonomic name.
Tip: Is there no any Genus that fits your creature? No problem! You can create your very own Genus just for your creatures! But don't forget to credit to with your own username if you have any and include the year of creation.
...How would being blocked on another wiki effect your account here? You can use your account here, its not banned cross-wiki unless wikia staff did that, and that only happens if you really messed up.