The vast majority of episodes feature no violence at all (unless you count arguing and shouting as verbal violence).
There are a few very mild scenes of wrestling, and a brief karate kick.
In another episode, however, we see some brief violent images, including a shadow of a criature that appears to tear a character's arm off (it doesn't really happen).
Some episodes focus on kids comically fighting with red paint or ketchup, intensively resembling blood.
One episode focuses on the death of an insect, including close-ups of its body, and there are multiple references to resurrection.
Series finale features a battle between two fantastical creatures, and a character who's mutilated.