What was the cartoon with monster hunters and it had a blond guy as main character?

You're probably thinking of "Monster Allergy", an Italian animated series that aired from 2005 to 2007.

* The main character is a blond boy named Elliott who lives with his eccentric grandmother, a renowned monster hunter.

* The show follows Elliott and his friends as they hunt down various monsters, often comedically.

Let me know if this is the cartoon you were looking for!