Okay, since it looks like next Monday’s episode is going to spill the beans on the nature of our favorite little green milk dud on Final Space, I thought now is as good a time as any to reveal my amazing theory on Mooncake’s origin.
The prevailing theory I have been seeing online is that Mooncake is actually Gary’s dad who was seemingly killed when the rift to Final Space was destroyed releasing Mooncake and the entity that created the Lord Commander.

I have to give a harsh no to this theory as, although the idea that John Goodspeed is still watching over his son is a nice one, we’ve seen that Mooncake can somehow communicate with Gary and I would think that, if Mooncake was Gary’s dad, he probably would have mentioned it by now.
No, my friends, I have an idea of what Mooncake is and, if I am right, the answer was right in front of us the whole time.
Remember this?

After he first meets Mooncake, Gary names him after a caterpillar his father gave him as a child. This, my friends, is — in my opinion — a heaping helping of hot and steamy foreshadowing.
Mooncake, a seemingly unkillable weapon that can destroy entire planets my screaming at them is, like the caterpillar, still in his larval stage.
Mooncake is a baby Titan.

Think about it: He is innocent, makes sounds like a baby, and he was the key to unlocking Final Space. What other entity, other than a titan, could generate that amount of power? A small little fella like Mooncake could have easily slipped through the breech that John sealed.
He’s a Titan.
At least, that’s my theory.