To me, personally, I really do love this. Only a few peices of critique; for one, as a big Doctor Who fan, and this is truley nothing to do with your drawing, but the 10th and the 11th Doctor would never be in the same place in 2 different bodies, because simply they are the same person (unless the 10th Doctors double came, or one of them got a ganger, of course). Now, fangirling aside, time for the drawing. This drawing has lots of aspects; its funny, its cartoon, its loved. You see it and smile! Your shading is perfect, but maybe a background would be good. But, on this accasion, I think not. Ignore me. Also, maybe a bit harder colouring. This is hard to explain, and I totally and utterly understand that people draw like this, and I like it, but maybe in this cartoon you could have drawn with less, whats the word,.. splotches. Example; Doctors trousers. Can you see what I mean? Maybe not like this on this artwork. But thats just me. Too, maybe a frame? Your choise, good without. I know im not a perfessional critique writer, but I have said what I think can make it better, and what I love about it. But I'll add. I really do love this, and it will be going into my favourites happily. A wonderful piece, a very well done to you. Oh, yes, I also love all their expressions too. Adds a great touch. Fabulous.
I love the originality of this piece of art; the original technique (as I haven't seen a style like this before) the (probably) most famous 'characters' of the characters (the outfits are well known to big fans, little fans non-fans as the episodes that featured them are... well, popular!) ...and the fact that 10th has decided to re-claim his fame by taking 11th's TARDIS !
The Dalek is drawn well, but I'm not entirely sure what it's doing; it appears to be standing still. (I know that it's quite obvious that the threesome are running into the TARDIS to get away from it but, I wanted to add something else in ). I assume you didn't want to add text, because I'd possibly add something to clarify what the Dalek is doing, like if it/he/she was chasing them, then add "EXTERMINATE!" But, it's quite clear anyway!
Overall, I'd say this is an excellent creation that show style, originality and pure brilliance! ____ Note: This is my first critique, and I really wanted to show my appreciation, as the first critique had spelling mistakes, and more opinion then necessary (in my opinion; how ironic!)