What are the favorite fatties you ever designed (or saw on custom magic)?

I’m working on a project making a magic-set with the premise “What if the rules of MTG were slightly different?” I don’t want to spoil what that difference is yet. But I think it would be fitting for that experiment to put in the most awesome cards, that don’t exist in regular magic yet – reworked a little, so that they make sense under the new rules. I’m going to ask for more types of cards in the future, but for now:
What are your favorite fatty-creatures? And may I use them for this set?

Btw, definition of Fatty: Any creature with big stats – that’s it!