Oh OOO, How Cute!

I was just looking at the canceled monsters in the wikia, then, I saw the green, That giant wobbly green joy of fn that spawns jellies... WAIT? doesn't the royal polyp spawn jellies too? so is what I found out
Both Royal polyp and Giant green jelly Both...
1: Spawn some type of mini jelly
2: Both have a attack other than spawning jellies
3: Both are in the slime family
Only difference is size, color, movent, attack type, and location
So what I can conclude is that OOO wanted the giant green jelly back, but knew it was too hard for begineers, so what did they decide? To get an almost identical version of the giant green jelly and stuff it in the Royal Jelly Palace!
How nice OOO!

Not quite. Giant Green Jelly spit off into mini jellies when hit, and also Royal Jelly already existed. Different mobs entirely.

The old royal jelly spawed minis. But they nerfed it and put polyps instead.
Green jelly is pretty much a crown-less color swap.

Oh, maybe. It's been a year since I last fought old Royal Jelly.
Herp durp