Maybe this is one of the "real" alien lifeforms who sent out spaceships with robots, which could be "organic" or synthetic, possible genetically engineered.
Either they are inside the Cuotl False God robots, inside the spaceship, or somewhere else and represented by holograms inside the ship or not visually shown at all.
The holograms Giacomo sees inside the ship could either be these aliens, avatars for the robots, or something else.
So we have at least three things - organic alien concept, alien holograms inside the ship, and mechanical robot gods.
There doesn't have to be a leader necessarily, they may have a different social organization than humans. Some sci-fi aliens have a hive or group mind.
The stuff hanging from its back, besides possible vestigial wings, may be a hook up to their technology.
[This message has been edited by alincarpetman (edited 11-02-2016 @ 09:08 PM).]