Glad to read that she/he woke up.
Comets are mostly water, water is a valuable resource up there as, you can heat it to make jets of steam to push yourself around. You can break it down into stuff that can be burned as rocket fuel, you can drink it and you can surround yourself in it to protect yourself and your gear from background radiation.
Moving a comet around would be tricky as it is likely held together very weakly by its own gravity, however some parts will hold together better than others so shearing a bit off and guiding it into earth orbit may be do-able.
If you want to pound the surface of the earth, you want nickel iron asteroids, swing them through a couple of gravity assists first and they'll make quite a dent.