Doctor Who: Every Prophecy In The Show - Explained
7. The Prophecy Of The DoctorDonna
One fascinating power that the Ood possess is their telepathy, a strong ability that we've seen them use on a few different occasions.
When the Tenth Doctor and Donna free the Ood from enslavement in Planet Of The Ood, we see this telepathy in action. Ood Sigma prophesizes the end of the Doctor's life by saying "your song must end soon", and then, he mentions "the DoctorDonna", foreshadowing a tragic turn of events that occurs at the end of Series 4.
"And know this, DoctorDonna. You will never be forgotten. Our children will sing of the DoctorDonna, and our children's children, and the wind and the ice and the snow will carry your names forever."
The DoctorDonna is a human/Time Lord hybrid that is created when regeneration energy from the Tenth Doctor's severed hand - which was chopped off during The Christmas Invasion - merges with Donna, giving her the mind of a Time Lord.
While Donna enjoyed heightened intelligence for a while, the Time Lord part of her soon began to overload, forcing the Doctor to wipe her mind in order to save her.
Interestingly, Ood Sigma also notes that "every song must end", so, on top of predicting the creation of the DoctorDonna, he may also have foreseen its demise.