when i was younger i had what i thought was a pretty cool idea for a sequel to The Thing (i saw elements of this in the different comic miniseries dark horse published years later)
a freighter crew is transporting pieces of the wreckage from the outpost back to the US (you'd never see macready or childs, they disappeared, so the ending to the first movie remains intact)
of course, thing gets loose, wreaks havoc on the ship, sucks faces and assimilates, tentacle-whips motherfuckers all over the place
a couple of the crew realize what would happen if it gets back to the mainland, so they try to destroy the ship while it's still in colder waters
they manage to destroy the ship and make it to a lifeboat
as they sit waiting to die or be rescued, the boat begins to rock violently, finally settling, and they see what caused it - a wave, building, and headed in the direction of land
the implication being, of course, that the thing is absorbing all the aquatic life as it is moving to where the people are
fade out on them staring at the wave disappearing over the horizon
well, as a fifteen year old i thought it was pretty cool, anyway