The title says it all really.
Following the little rascal's attack on his stepmother whilst everyone is celebrating another Fowler wedding and Peggy's suicide. (Need a Harry Hill look-to-camera here...), I thought that the one thing that could make some of the old Tom Baker Doctor Who adventures even more scary and horrifying would be the addition of Bobby Beale.
Here's some ideas. I'm sure there are plenty of others but three is enough to be honest.