Goblin King level 1 has been confirmed and the stats are here and same with its ability but all that needs to be done is the dps in ability and stuff.
Cost: 50,000 dark elixir
TH unlocked on: 10
DPS (for level 1): 75 but on resources: 215
Regen Time: 30m
Ability: The goblin king turns gold and he spawns 6 goblins surronding him and when the goblin king turns gold he hits resources 5x faster for 5 seconds. The goblins around him make the goblin king get more resources without taking damage.
So far he has 20 levels and more will be added soon.