Complete list of character cameos?

I'm going to go see the film again, but so far I noticed:



Bereet

Cosmo The Space Dog

Howard the Duck

Chitauri (In a containment cell)

Dark Elf (In a containment cell)

Celestials (I forget which Celestial specifically was shown. Maybe it was Oneg?)

The Watchers? (The robed beings that briefly held the infinity gems)