4. The Abzorbaloff
Now the Abzorbaloff may have only been in one episode, but it needs to stay that way. Ask any Whovian for their opinion on the episode "Love & Monsters", and I can guarantee almost 98% of people will say they hated it. Personally, I liked the character of Elton, and his relationship with Jackie was wonderful. But once again, the development of characters affected the writing of the episode. It may not be very fair to say that the Abzorbaloff was a bad idea as it was designed by a Blue Peter competition winner, but there were still flaws with the alien that bothered me. What bothered me was what he did with his victims. After absorbing them, their faces would show up over his body. What would happen if he was to absorb 50 people. Is that possible? It just seems a major flaw to me that he may only be able to kill a certain amount of victims. Luckily enough, it seems he really was just a one-off villain, so hopefully we won't have to see him again.