If you look closely in the first shot in the museum, you see Fred Flinstone encased in amber.
Zodiac Man: Welcome, Space Ace, I've been expecting you. Now we can continue with our little game. You know, the one where you lose.
(Space Ace and the mutts bounce around in the giant flying metal goat and it explodes)
Dipper: Where'd the goat go?
Space Ace: Cos', I don't think he had the stomach for us.
Zodiac Man: Very well. To show you how sporting I am, we'll play a little game of cat and mutt.
Space Ace: Let's move it to the Ace Ship. I really want to nail this dude.
(they all run toward the ship except Dipper)
Dipper: Is he going to use real nails?
Space Ace: The word is that the Zodiac man is after this ring and that's why we're here.
Astro: It's safe with us on the job. Right, Space Mutts?
Cosmo: For sure! That turkey won't get within fifty yards of that ring.
The museum name, The Moona Lisa Museum, is a direct reference to the famous painting, The Mona Lisa. The famous portrait is pictured on the museum.