Aslan

Aslan was a talking lion who existed in the Land of Fiction. When the Seventh Doctor was wandering the void outside Arandale, searching for Arandale Keep, he encountered Aslan, who wished him "Godspeed". After that, the Doctor found himself heading the right way, along a path delineated by various beautiful markers. (PROSE: Conundrum)

Behind the scenes
Aslan is a character from The Chronicles of Narnia, C. S. Lewis's series of fantasy novels, in which he is the incarnation of Jesus Christ in the world of Narnia.