Dialga, with his large steel forehead, looks down upon a bunch of his worthless minions.
Dialga is the God of Time and part of the Pantheon of The League. He is quite a large creature, created by Arceus out of steel at the beginning of the Universe. It was Dialga who created the Time Lords to keep the laws of time in check, preventing the flow of time being interrupted. Dialga ignores both renegade Time Lords, The Doctor and The Master, as, despite betraying their race, still obey the laws of time.
Dialga also granted the Time Lords access to the TARDIS', allowing them to travel through time and keep it safe and sound.
Dialga is partnered with Palkia and Giratina, the Gods of Space and The Void respectively, in the Creation Trio. These were the first beings created by Arceus at the start of time and, along with him, shaped the Universe.
Dialga was the being that drove Cult of Skaro member Dalek Caan completely insane. He blocked Caan's temporal shift into the time-locked Time War and Caan, realising that Dialga was a superior being, was driven insane by the thought of a creature more powerful than Daleks. He then went on to preach Dialga's word to the Daleks, a word that they would never heed. As a form of revenge, Caan lied about the Dalek's invincibility, leading to their death at the hands of the Reality Bomb.