I saw a woman taking in a group of small children to see the Watchmen movie several years ago, in spite of its rating. She must have mindlessly thought 'all superhero movies are suitable for kids'.
I took my daughter to see "Howard the Duck" when she was 7. She survived and, miraculously, I was not arrested for child endangerment.
I still remember the migraine that so-called film triggered--a full-blown attack, complete with aura and vomiting and about a day and a half of photophobia and severe head pain.
Ralph Bakshi was doing the same thing 40+ years ago. None of his animated films are for kids, especially the ones that are R-rated, which most of them were. & his film version of Fritz The Car received an X, IIRC. His version of The Lord Of The Rings, while being PG, is not really for kids either.
Bakshi did however do animated TV shows & TV specials for kids.