Dragons guard treasures so that Zara can't just walk in and steal everything.

Let me tell you this: if you wish to join Zara's personal Treasure Hunters pack, you're probably a fool... or maybe someone who has no personal interest in shiny coins, precious gems and valuable stuff in general... for the most part.

You see, the Hunters, Adventures, Warriors and so on in this group do not hoard riches for themselves, but instead "donate" them (willingly, most of the time) to impress Zara herself. For whatever reason. A sort of tribute, or a competition, if you wish.
She didn't really ask for this (having people following her around is the last thing she wants) but eventually they started doing that after seeing her roaming the lands stealing and taking anything that shines for no real reason.

Rumors and legends started to follow...They say that, if you bring her enough riches, she might start to like you.
But don't get fooled by her childish smile or innocent eyes when you gift her a shiny.
Truth is: she'll just expect more and more from you in the future... without giving anything back.

Some say she's a dragon in human form, others that she's a demon of sorts.
What we know for sure is that she appears in different worlds and eras without a clear logic and her appearance is somewhat similar in each case: blood red hair, light green/blue eyes, pale skin.

She's been seen traveling with a valiant knight in multiple occasions. Maybe he's immune to whatever she does to people. Or she simply uses him as a distraction for the monsters and foes guarding her beloved shinies.