12 ^ 2 star signs
This isn't a serious proposition, because I think it would take quite a bit of work (i.e. for once I'm factoring in the time spent coding it) and frankly, while maybe a mildly interesting idea it isn't that great. However...
If we arranged the present star signs row-by-row on a spreadsheet, then for 11 more columns we could add 12 more star signs.
Example:
(predators): Wolf, cat, snake, etc.
(plants, or trees): tree (or oak), fern, rose, lily, etc.
(birds): raven, phoenix, dodo, vulture, etc.
And so on.