Can Aniimo eggs be found in the open world?

Picking one up is as simple as it sounds. Walk to the egg and interact with it once, and it is yours. There is no minigame and no second step. The only complication is placement: some wild eggs sit somewhere you cannot reach on foot, and getting to those means using an Aniimo to cover the gap. So a visible egg is not always an immediately collectable egg, and it is worth remembering which ones you had to leave behind.

Before you commit to hatching, check the biome icon on the egg. That icon shows the pool of Aniimo that can come out of it, which is the only advance information you get. It narrows the field, it does not pick the result. Hatching can and will hand you duplicates of Aniimo you already own.

What hatches also arrives with a fixed Potential grade on the same four-tier scale as anything you catch: Common, Good, Elite, Perfect. Fixed means you take what the hatch gives you. Two items change that. Hatching an egg with an Aniipod Ultra guarantees at least Elite. A Sparkling Cube applies during egg incubation, forces the Sparkling variant, and since the launch update grants guaranteed Perfect Potential. Full incubation mechanics are covered in the linked article.

Egg Heist eggs arrive differently

Open-world eggs are not the only source, and the other main one does not work the same way. Eggs extracted from Egg Heist are not handed to you on the spot. They are delivered to your in-game mailbox, and you have to go and collect them from there before you can do anything with them. Once collected, they behave normally and hatch into usable Aniimo like any other egg.