There are two possible avatars to be collected named ‘Korbat – Royal’, and they are mutually exclusive – meaning if you have one, you cannot have the other.
To achieve the Royal Boy version (top), have your account’s gender set to Female and visit the Petlookup of a Royal Girl Korbat, for example this one found by clicking here.
To achieve the Royal Girl version (bottom), have your account’s gender set to Male and visit the Petlookup of a Royal Boy Korbat, for example this one found by clicking here.