yeah. like if they had the oil derrick as a multiplayer stage, there should be a spot were you call the leviathan using this trust siren thing. the leviathan appears, and would circle the map and just lay waste to everybody else (or everybody on the enemy team). like it would blast people at random, grab people and throw/eat them. it would be sick.
maybe it would just be it's tentacles that circle the map. like the tentacles would pick people off randomly, then for the big finaly his head pops out in an area were there are the most players, shoots fire for a few seconds, then grabs an unlucky player in his mouth before leaving(if a player is in range of his mouth)
I think that's a great idea. The more what the hell just happened moments the better. I don't know why people are so set on old and stale game play. A little variety is a good thing, and a mad leviathan wreaking havoc on the map will give people one more thing to think about (and would hopefully be something one could use to their advantage).