Is it bad to call kids mojaditos?

[Juerte23]

Is it bad to call little kids mojaditos?

[Rusty]

Not if you're Mexican, I would guess, but I'll defer to a Mexican.
Many times, what we English speakers would consider to be a slur on our character, latinos will use without a second thought. It's OK for a latino to call another latino gordo, flaco, or viejo, but we English speakers would take offense.

The English meaning of the word in question is pejorative. Consider your audience.

[AngelicaDeAlquezar]

Yes, it is.

To call latino people "mojados" expresses the assumption that they entered the USA illegally (by swimming through the Rio Grande), which underlines a rather prejudiced stereotype. If they call themselves so, as Rusty said, that's something they may do among equals, but it's something that would hardly be welcomed from someone out of their group. That, added to the fact that it's children who would be called a pejorative name, may aggravate the parents.