I haven't made one of these before, so I'm gonna keep it pretty simple.
Dual-Talented Human (Mutation Warrior) 3
VMC Barbarian.
20 Point buy:
Str: 20
Dex: 12
Con: 16
Int: 8
Wis: 12
Cha: 7
The feats aren't all that important, but I'd go:
1: Power Attack, Weapon Focus (Greatsword)
2: Step Up, Bravery +1
3: Mutagen(Mutation Warrior), Rage(VMC Barbarian)
From there, it can be built pretty much however you please, though the intent's for massive Two-handed damage. You can use feats to increase your rounds of rage beyond level+Con.
With this, you can get 28 strength at level 3, with a mere six intelligence. Only for six rounds a day when you first get it, but feats and con boosting can get you above that.
To really commit to the "Body of a Monster, Mind of a beast" thing, play an Orc with 22 strength and 5 Int. After popping your mutagen and rage, you're sitting at 30 strength and 3 int.