Colossus

You have trained your body to be able wield larger and larger weapons, just as effectively as smaller ones. As a result, you gain the following benefits:

• You Strength score increase by 1, to a maximum of 20.
• You gain the ability to wield two handed melee weapons in a single hand, with no penalties to attack or damage rolls. 
• Alternatively, you are able to wield weapons designed for creatures up to one size larger than you, without any penalty to attack or damage rolls.