How do you get Unicorns to spawn?

Excuse me, but could you please clarify what you mean by "Unicorns spawning"? Are you referring to a fictional creature or is there a specific context, such as a game or application, where "Unicorns" are mentioned? If it's the latter, could you provide more details about the platform or system in question? Without that information, it's difficult to give a direct answer, as the process of "spawning Unicorns" would depend heavily on the specific rules and mechanics of that particular environment.