There some mild innuendo like characters uses female disguise to distract male characters.

Constant strong cartoon violence. No blood but this show doesn't back off from showing skinning, surgery, and guts although comical

Guns don't appear in season 1, but guns later appear in later seasons.

Due to TV-PG, the show has some dark theme, and it might disturbing to some viewers.

But since this is a cartoon, he appears ok in the next scene.