And, we don't know just how much he was stopped by Thor. We know he went over the cliff and he was smoking. That's all.
Mangog, in addition to how he increases his power, has matter manipulation, shape-changing and energy blasts. He also has been hinted as having teleportation powers, since he has always been able to bounce from planet to dimension to planet, etc, without any apparent means of travel.
On top of being a Validus-class head-smasher.
Mangog FTW.