Marvel's The Avengers movie 31 minutes 23 seconds

Can someone please tell me what is moving in the background at the aforementioned timeframe? It looks like a tentacle or worm but I really don't know. I've scoured the internet looking for information but I can't find anything relating to the subject. It seems this hasn't been brought up anywhere. I'd greatly appreciate an answer. Thanks in advance.

16 time in 7 days i use this image.

Also, this cant be serious, you keep posting the same thing over and over again.

Also think i dont go to Off Topic.

The part where Loki is talking to The Other? I'm pretty sure it's one of those big creatures that's seen in the final battle.

Yeah, I think his name is Leviathan, is the giant alien that Hulk punched and knock him with one shot.