Has there ever been some sort of River Troll?

[Aeolius]

And just to confuse things, add a few half-scrag merrow (aquatic ogres) and half-merrow scrags

 

[DaveStebbins]

An intelligent (or perhaps merely cunning) scrag makes a great villian for low-level characters. Years ago, I used one to recreate " The Creature from the Black Lagoon" as an adventure for first and second level PCs and it was a lot of fun. Maybe I should update it to 3E...

-Dave

 

[Wippit Guud]

The ever-dreaded forum troll...

 

[rounser]

Not forgetting the original FF's Spectral Troll and Giant Two-Headed Troll.