The flower idea is definately visually appealing. But the issue I could see with it could be the concept. I mean, it kinda needs to be weaponized or explained with something else, rather than arbitrary overgrowth for something so specific and elaborate, right?
I mean, if you would see that creature in a game, what would you immediate thought be? It's that it's either a very dangerous weapon, or that it fulfills an important function, or that it's the creatures weakpoint.
And if it's the weak point, it's kinda weird how heavily armored he is, but not on his weakpoint. XD