At least two on-screen paintings featuring naked (albeit nipple-less) women in the episode "Rip Van Flintstone."

In season 2 episode 12 titled masquerade ball Barney tells Fred he wants a costume where he will look tall Fred tells him "How about another head" to which Barney then says "another one what do I need 3 of them for" implying that he already has 2 heads one up top and one in another area below.

Mild comical slapstick violence.

Fred Flintstone can be seen getting his face punched, his foot crushed by a bowling ball, getting his butt bitten by an animal.

Fred gets super drunk at the malt shop in one episode.

There was smoking in the very early episodes.

None.