Bring lots of cash, especially small bills, so you can make change easily - or in case you catch an end-of-show deal. I would also have a fanny pack or cash box to keep it in.
Bring a friend to help with setup & takedown, and so you can step away for bathroom breaks, to check out other tables, grab a bite to eat, etc.
Bring snacks and drinks, you may not have time to go buy lunch.
Bring a way to heat your snakes in case the venue is cold. One of my first expos was in a fire hall - in February. While the heat was on for the day it was normally unheated and uninsulated space, so the most it ever got inside was 65*F at the end of the day. From experience I knew it would be cold so I covered the table with a heated massage table pad and then put a tablecloth on that.
Bring a tablecloth.
Bring hand sanitizer.
Since you don't have a lot of animals look around for any extra equipment you aren't using and want to get rid of, if you have any. Mark it at half retail and it will move.