Zhu Hong is a Snake Yashou who grew up in the Snake Yashou forest. The only relative of hers we meet is Fourth Uncle, the Snake tribe leader.
It is unusual for Snake Yashou to live among humans.
Her job in the SID is unclear, she does all sorts of administrative work, but also some field agent work (ep3). She acts as liaison for the Snake Tribe.
Zhu Hong becomes leader of all Yashou tribes by making the ancient sapling sprout. (ep37)
Zhu Hong has a strong fighting spirit. She can exert energy, which is shown as her eyes glowing red and shooting bursts of red energy.
She can also hypnotize people with her power, which backfires when she tries it on Shen Wei. (ep10, ep11)
Zhu Hong has a snake tail, which is usually hidden, but can be seen briefly in episode 1. All Snake Yashou can probably transform completely into snakes, but this is never shown.
Zhu Hong is sometimes called on to perform tasks "only a woman can do," e.g. to comfort the rape victim Professor Zhang Ruonan (ep3), or to help Wang Zheng wake up (ep12?). But she is not very good at them. She prefers making threats to showing emotions.
She is a fierce fighter.
Zhu Hong is secretly in love with Zhao Yunlan until she confronts him about it (ep31), where he lets her down gently and offers to become friends. She slowly starts to get over her unrequited love from that point on.
Zhu Hong is at first too shy to accept the challenge to become Yashou leader, but once the position has been thrust upon her, she seems happy about it.