Double curbstomp: Greenland(movie) X Godzilla: The Planet Eater.
After the first few bits of Clarke hit the planet and cause untold devastation, John and his family reach shelter just in time as the last piece of the comet flies overhead. But. It doesn't strike the Earth; a red beam strikes it just before impact causing it to explode near the ground(causing even more devastation!)
And right at ground zero is something even worse than a planet-killing comet: Godzilla Earth. Who has risen to take revenge upon all of humanity.