PKHeX/PKHeX.Core/Legality/Structures/Nature.cs

namespace PKHeX.Core
{
    /// <summary>
    /// Nature ID values for the corresponding English nature name.
    /// </summary>
    public enum Nature : byte
    {
        Hardy, Lonely, Brave, Adamant, Naughty, Bold,
        Docile, Relaxed, Impish, Lax, Timid, Hasty,
        Serious, Jolly, Naive, Modest, Mild, Quiet,
        Bashful, Rash, Calm, Gentle, Sassy, Careful,
        Quirky,

        Random = 25,
    }
}