* Pelle: This is a common and relatively mild term, often used for a mischievous or naughty child. It's closer to "rascal" or "imp" than a truly insulting "brat."
* Kapinamainen lapsi: This translates to "rebellious child" and is suitable if the "brat" is characterized by defiance and disobedience.
* Hurskas: While literally meaning "pious," this can be used sarcastically to describe a spoiled and self-righteous child.
* Öikypoika/Öikytyttö: (boy/girl) This translates roughly to "spoiled brat" and is a more direct, and negative translation.
* Pikkupiru: This means "little devil" and conveys a sense of mischief and naughtiness.
The best choice will depend on the context. For a general, somewhat playful meaning, "pelle" is a good option. For a more negative and insulting connotation, "öikypoika/öikytyttö" is more appropriate.