If you look at the artwork for the Egg with the tiny Alien on it, the Deluxe Edition of ALIEN ANTHOLOGY BLU-RAY set, there are three different angles of the Alien. Front, Profile, and from the back.
The pic from behind, on the far right of that photo, details a fifth giant horn in the top center of the ALIEN's back, just below it's neck.
Strange.
Ive never seen that before. I wonder why it's there.