The 13th Doctor is played by Liam Neeson. His catch phrase is "Let's do this!" He may call himself The 13th Doctor, but he's really the 15th incarnation, because of The War Doctor and The Time Lord Victorious. His companions are Romana, followed by Anna and Henry Stanford. He never wants to change, which messed up his regeneration into The 14th Doctor in the Series 12 finale.