Similarity ensures. One travels through time, another travels through dimensions. A hedgehog and an alien... pony... thing, from what I've heard. Allons-y~!
(Forgive me, I dunno much about Doctor Who.
____________________Sonic DashScootaTailsAmy PieTwilight BlazeFlutterCreamRouritySilver WhoovesGildowBig KnuckletoshBigzy DooBunniejackVector ScratchSpike CheeseSuper Rainbow- Set 2 -
Special thanks to *RichHap [link]