I always wanted to try playing a character based on other types of monsters like trolls for example. This is because they are a character option in world of Warcraft and not to mention skylanders. These presents two types of playable trolls: ones who have industrial revolution  ideals and one who is more barbaric  and works  on a strength based leadership system. Another idea was an amythst dragon  based off of flashwing. Or how about many  different zora types. Or even the two rito types. Or Spyro. 

Probably a better question for Homebrew & House Rules but it wouldn't surprise me if there isn't already a suitable Troll race in the Homebrew Race Lists