Heres the thing about the Mara. Its actually a pretty good monster. Its genuinely frightening when its possessing people and making them do that horrible hyena laugh. Tegans dream sequence with the Mara is probably one of the creepiest things youll see on Doctor Who. The problem rears its big ugly head when we actually have to see the Mara which is a big, naff-looking snake. To be more precise, its a small, live snake, then its a giant plastic hose, then its a puppet. Of a big, naff-looking snake. So ten out of ten for the fantastic concept, and minus several million for the execution. What do you think? What are some of your favorite low-budget creations on Doctor Who?