"Do you know the thing I hate most in all the world? Turtles! Now, I look in the mirror, all I see is you! And I hate you even more!"
— Brand-new mutant turtle Hun, Turtles Forever
Donna: They...they turned him...into an Ood.
Donna:...He's an Ood.
Doctor: I noticed.
Donna: It's weird, but...being with you, I can't tell what's right and what's wrong anymore!
Doctor: It's better that way. People who know for certain tend to be like Mr Halpen.
— Doctor Who, "Planet of the Ood"
You were wonderful - everyone told you so. Thus, you really didn't have much time or use for people who didn't have anything you wanted. Like that disgusting bum who approached you in the subway station and asked you for change. You dismissed him from your presence with a contemptuous curse. Your action didn't go unnoticed, and you had a visitor that night.
The pain of the Embrace and transformation was nothing compared to the hysteria you felt when you looked in the mirror your sire gloatingly held before your face. The mirror shattered, and so did you.
Everything you owned, everything you were, had been based on your looks. Now look at yourself. Smile.
Over the days and weeks following the massacre, the survivors underwent... changes. Their musculature shifted, and their bones reworked themselves painfully. Horns sprouted from Safari Joe's forehead, while his wife grew fatter and fatter, her body bloating into a morbid sack of gelatinous flesh. The Ringmaster's eyes grew thick with milky cataracts, and a leathery tail emerged from the base of his bowed spine. Old Delvin Tremblay found himself with an extra pair of arms and webbed fingers, and his skin became slick and warted like that of a frog. Sins from past and present rose to the surface as the stains on souls manifested themselves. All the circus folk suffered deformities; none were left unchanged. To their horror, they had become the freaks they had destroyed.
—"The Whispering Wood," Mysterious Places
"Albert": You cannot hope to imprison us!
The Doctor: Ah, I'm afraid you won't be able to time travel out of here. You're no longer Elder Gods; you're human beings.
"Peggy": Human beings?!
"Albert: These mortal bodies we inhabit - who are they?
The Doctor: A delightful couple I met called Albert and Peggy Marsden. Well I mean, not the real Albert and Peggy - the real Albert and Peggy are safe and sound in a version of history where the nuclear war never took place. No, you're looking out through the eyes of the alternative Albert and Peggy from the timeline you created.
"Albert": But why?
The Doctor: Why? To give you a chance to walk in their shoes...