Krislok

Krislok was a Graske who enountered Sarah Jane Smith and her friends.

A Graske named Krislok worked as an agent of the Trickster. This was because the Trickster had pulled him from his timeline at the moment of his death. Under the Trickster's orders, it first attempts to erase Maria Jackson (who had been protected from the Trickster by the Verron Soothsayer's box) from time by kidnapping her and stopping her from ever existing, although the process goes slightly wrong and she briefly ends up in 1964 before being recaptured. It is later sent after her father, Alan Jackson, although he manages to tie it up and forces it to reveal how to put Maria 'back in time' and rescue her from limbo. It later manages to free itself and teleports away. (SJA: Whatever Happened to Sarah Jane?)

While still working for the Trickster, Krislok poses as a little boy in order to lure Sarah Jane to 1951 - to the time of her parents' death. After the Trickster is successful in creating an alternate timeline where he manifested corporeally on Earth in 1951, the present day is a desolate wasteland where the Graske enslaves the few surviving humans to mine for resources so he can extend his reach to other planets. Rani and Clyde (protected by the Verron Soothsayer's box) implore the Graske to explain why he is a slave to the Trickster. He relays to them how as one day when his ship was about to explode in space, the Trickster offered to save his life in exchange for eternal servitude. The Graske opens a time fissure to allow Rani to tell Sarah Jane where the Trickster is set to manifest. After the timeline is restored and the Trickster seemingly destroyed, Clyde gives the Graske the box to protect him should the Trickster ever return and seek to punish him. (SJA: The Temptation of Sarah Jane Smith)