Geoffrin (The Art of Death)

Geoffrin was a rich kid.

Timeline 1
He visited the Horizon Gallery with several other rich kids and wasn't interested in anything but the Paradox. Geoffrin was bored when Penelope showed him around. He talked with his friends on the telephone and ate during the tour. He treated Penelope disrespectfully. When another rich kid dropped a sandwich on the floor, he told Penelope to pick it up. However, Amy Pond told Penelope not to pick it up, and Penelope did not do this. After this Geoffrin and the other kids were attacked by a creature. He was killed by the creature.

When Penelope later realised that her older self was the creature and the paradox, she stopped herself from becoming that creature by sacrificing herself. (AUDIO: The Art of Death)

Timeline 2
As the Paradox did not exist, Geoffrin wasn't killed by it. (AUDIO: The Art of Death)