The 1 Million Visits Egg was added to the game on 7/03/2022. This egg featured six pets. Three pets were epic tier, two were legendary tier, and one was mythic tier.  The cost to open the 1M egg was originally set at 1 trillion gems but decreased to 750 billion gems soon after. This was the first egg you could spend gems on and the first milestone egg released.

(Fun fact: The 2nd legendary, Mantis, was based on a Pokémon - Scyther)