The space jockey's created some pretty weird xenomorph for there experaments, the biggest one "ten times bigger than a queen" looked like a chestburster
http://www.the-artfile.com/gallery/artists/giger/alien3.jpg
If you look to the side you see about 12 space jockey's, they look like ghosts, they are tiny compared to this thing, here is a reguler space jockey
http://www.moviecitygeek.com/DVD/images/alien_3.jpg
Pretty big huh? amagine how big a chest burster 12 times that size would be
http://www.the-artfile.com/gallery/artists/giger/alien3.jpg
about that big.
in space...
no one...
can hear you scream...