A self-absorbed teenager, who joins a Special Species Government Organisation, has to protect a rare tiger from a relentless, reptilian poacher.

It seems like everyone's getting confused by and hung up on the reptilian poacher.? Because of that, I would suggest making that part more clear or just get rid of reptilian and leave it as a relentless poacher.

I could be wrong, but a poacher wouldn't be another animal, right. It suggests to me it would be a sentient being, a reptilian alien who has come to Earth to hunt rare animals. If I'm right and it is an alien, I think you should include that in the logline.

What do you mean by Species?

Why is a tiger in danger from a reptilian poacher? I would think a turtle, snake, or lizard ... or you can change the poacher into an infamous game hunter.