The rarest pet tier in Bubble Gum Simulator Infinity is Infinity, sitting above Secret and Celestial, and it's crafted through the Crystal Altar using Crystal Ore rather than hatched directly from a standard egg.

Yes, you can still get items from past events through a shop, even though they're no longer obtainable in-game once the event that introduced them has ended.

Some islands and eggs are so hard to find in the game because certain hidden areas have historically had discovery rates as low as 0.002%, making them impractical to find through normal play alone.

Yes, you keep the pets, coins, and materials included with your purchase, exactly as shown in the listing.