To maximize your chances of hatching any huge pet during these events, ensure you use (like Rose Tokens for the Luck Machine) and keep your Luck Machine fueled to avoid having your rare odds halved.
Since it is no longer obtainable through active event hatching in the current game, the most common ways to get one now are: Hatch Huge Easter Cat | Really Really Huge xD |...
Another rare drop from the Hidden Egg Hunt. To maximize your chances of hatching any huge