Kurgan said:
The space slug looks fine. Why change it? It's a fantastic creature that makes absolutely no sense in real life, so if we were going for strict realism there would be no creature, period. Delete the whole scene and just say they flew out of a normal asteroid.

The only part that needs fixing are the bad matte lines on the teeth in those last shots (and maybe that strange blue effect that everyone mentioned that's now been removed). Everybody knows it's a monster mouth except Leia, so what?

If you really want to improve the scene, turn it into one of the sand worms from Dune, and insert the line where Dr. Kynes is talking about blessing the Maker and his water. ;)

This reminds me of a discussion that bounced around some months back (the nature of which is not for this place).

Star Wars isn't science fiction, it's space fantasy, it's Sinbad with space ships.

While a creature like the space slug might exist out there somewhere it wouldn't look like that and would possibly feed off chemical deposits found in the asteroid field and resemble a marine filter feeder, the teeth make no scientific sense at all but that's ok because it doesn't have to be a scientifically viable creature, it's fantasy.

But for a fantasy story to work it has to make sense within the fantasy realm that the story is set in.

Han flies through the open mouth and initially believes it to be a cave entrance, Leia is still convinced it's a cave when the mouth is shutting and it makes sense to make the creature look more of a realistic (in a fantastic sense) threat.

So changing the mouth to look more like the sort of thing that could be mistaken for a cave and making the creature look more convincingly scary makes sense.

But it is up to Adywan if he wants to do that in his edit.