https://www.dndbeyond.com/profile/Magmacube90/characters/45142823

This is my Grung Fighter. Can you please rate him, Place your own build of a grung fighter, or Suggest improvements.

I'd be tempted to switch out one of your feats for sentinel, it's very good for echo knights.

You seem to have unarmed fighting style twice? 

With strength being 20, you could be using a strength based weapon with better damage dice than the rapier

Thanks I have edited it a bit

https://www.dndbeyond.com/profile/Magmacube90/characters/45405746

You have 2 proficiencies to choose, and I'm still not sure what tavern brawler gives you that other feats wouldn't. 

 GWF would be standard if using a 2hnd weapon 

It allows you to grapple as a bonus action if you unarmed strike someone so then you can poison them from being a grung