Raining Men of course, or alternatively, raining Sperm Whales or Blue Whales, cause those would cause lots of damage.
Being a Marine Biology major, I knew it was absurd, especially since it was that many sharks, and that all of them were alive. The movie was a blast, because it's a cheap movie made for laughs, and it delivered that in full, especially at the end. If the second movie is as ridiculous, or even more than the first one, I know I will love it. Next up will be Whalenado, a Pokémon parody with 1000's of Wailords being flung across all the regions.