The departure of David Tennant inspired me to draw something celebrating the history of Dr. Who. I've been a Whovian for years and years. (For the record, Tom Baker will always be my favorite, followed by David Tennant and then probably Sylvester McCoy. Debate amongst yourselves.)
I took several liberties with the TARDIS but based it mostly on Tom Baker's era.
This is all Photoshop, I wasn't really keeping track of the time but probably around 15-18 hours.