This episode reveals that Megatron is Savage/Noble. As he explains, he finally managed to separate his robot form from his organic self, but his spark remained in the organic half.
Blackarachnia: (About Noble) I can't say why, but something about him gives me the creeps.
Rattrap: Well let me see. Is it his eyes? The hair? Or maybe it's his little tendency to keep turning into a giant, wigged out, flesh eating gila monster?!
(Rattrap is looking through Megatron's computer)
Cheetor: What are you doing? Are you trying to find the sparks?
Rattrap: No, I'm reading the Sunday funnies. What do you think I'm doing?
Rattrap: Now that Megatron is a floating tribute to Unicron.
Unicron is the giant, planet devouring Transformer first introduced in Transformers: The Movie. When Unicron was destroyed, his head was sent into orbit around Cybertron, and remained there for much of the post-movie series.
Title: Prometheus Unbound
In Greek Mythology, Prometheus was a Titan who sided with the Olympian gods in their war against his people. However, when he stole fire from the gods and gave it to humanity, Zeus had him bound to a rock in the Caucasus Mountains. There, Prometheus' liver would be eaten by a giant vulture (or eagle, depending on the source) for many years until the hero Heracles freed him.