Here are some options depending on the context and what you want to emphasize:
If you mean "crazy" in a fun, playful way:
* Keiki pupule: This literally means "crazy child," and it's a playful and affectionate way to call someone a little crazy.
* Keiki ʻōpūʻō: This literally means "belly-button kid," but it's used to mean someone who is full of energy and a little bit mischievous.
If you mean "crazy" in a negative way:
* Keiki haʻahaʻa: This literally means "low child," but it's used to mean someone who is out of control or disrespectful.
* Keiki hewa: This literally means "wrong child," and it's used to mean someone who is behaving badly or causing trouble.
To be more literal:
* Keiki ʻinoʻino: This literally means "evil child," but it's not as commonly used and can be considered quite harsh.
Ultimately, the best way to say "crazy boy" in Hawaiian will depend on the context and the tone you want to convey.