The Ood Elder was the leader of the ruling council on the Ood Sphere in 4226, identifiable by the external forebrain.
History
When the mind of the Ood became plagued by nightmares of the Master, the Elder had Ood Sigma send a telepathic message to the Doctor. The Doctor received this communication very shortly after the events on Bowie Base One in 2059, to bring him to the Ood Sphere. (DW: The Waters of Mars)
When the Doctor arrived on the Ood Sphere, the Elder and the other Ood that were present showed him a vision of the Master. Despite the Master's death and refusal to regenerate after the Year That Never Was cancelled itself out, the Ood Elder assured the Doctor that the Master would soon return. He also showed the Doctor images of Wilfred Mott, sitting at a table, looking upset, of Joshua Naismith and Abigail Naismith in the Naismith mansion, though at the time he did not recognise him, and an image of Lucy Saxon, imprisoned; the Ood were unaware of her part in events, and the Doctor explained her history with the Master to them. The Doctor again insisted the Master was dead, but the Ood Elder showed him something he hadn't seen; an old woman recovering the Master's ring, allowing him to be reborn. The Doctor tried to leave in panic, but the Ood Elder remarked there was more; "The Master is part of a greater design, because a shadow is falling over creation. Something vast is stirring in the dark!"
At this point, the eyes of the Ood Council turned red. The Ood Elder explained that the Ood had gained the power to see through time "because time is bleeding. Shapes of things once lost are moving through the veil, and these events from years ago threaten to destroy this future, and the present, and the past!". When the Doctor asked what they meant by this, the Ood Elder replied "This is what we have seen, Doctor. The darkness heralds only one thing...the end of time itself!"
Horrified, the Doctor then left, returning to 21st century Earth to stop the Master.
The Ood Elder, along with the other Ood, telepathically sang with the Tenth Doctor before he regenerated. (DW: The End of Time)