The Trickster

The Trickster was a strange being that thrived on chaos. It could also remove humans from Earth's timeline, and influence events of Earth's history. It had a mouth of sharp teeth, with no eye sockets and was always hooded.

The Trickster had removed Sarah Jane Smith from Earth's timeline, and influence events so she died in the place of Andrea Yates (who should have died in the original timeline). The Trickster also stopped the aliens that Sarah Jane would have faced to leave the Earth alone (i.e. Luke Smith is never born, because the Bane never invaded). The Trickster had also duped the services of a Graske to kidnap Maria Jackson and her father. (SJA: Whatever Happened to Sarah Jane?)