As the moon is about to collide with the Earth? Think of the effect the moon already has on the Earth. It causes ocean waves without fail(the same way the Earth pulls on the Moon[which is why the Moon orbits the Earth] the Moon also has a pull on the Earth). What would happen if that object which already has a significant pull on the Earth gets gradually closer?(considering it's on a collision course with the planet)
As far as I know, you'd have plenty of tidal waves and Tsunamis. There aren't any other significant effects the moon has on the Earth when compared to its influence on the ocean. I think it'd also affect how much planet Earth would wobble. Yes, the Moon makes our planet wobble. It's just such a weak pull that the wobble is too insignificant to bother with.
/tangent: Even planet Earth makes the sun slightly wobble. I know you probably didn't get as much info as you wanted, but believe it or not, I know more about black holes, quasars, and neutrons stars more than my own planet and its moon
. Let me know if you're satisfied or not.