Squick / American Dad!

• In "Stannie Get Your Gun", after Roger tricks him into thinking he's adopted, Steve proceeds to give Hayley, his own sister, a french kiss. Even worse is that Steve implies he's been wanting to do that for a while.
• Stan gleefully giving his mother a bath while singing an incestuous parody of "What Do You Do With a Drunken Sailor?". It was so bad, it traumatized Roger into drinking again.
• Steve and Stan with huge boobs in "Helping Handis", especially the ending montage with them washing cars.
• "Shallow Vows": Francine's appearance after she quits her beauty regime, with her becoming hairy and obese.
• A sickly mother cat giving birth to 3 kittens in front of an awakening Francine from "Less Money, Mo' Problems".
• The tortoise dragging what's left of the hare's horribly mangled corpse across the finish line at the end of "Delorean Story-An".
• The brothels in "Toy Whorey". Stan and Steve's first stop is the home of a fat, old hooker with both her legs missing, who slaps a tortilla between her thighs. The second one has a man who uses Senor Wences-style hand puppets as hookers (one of which has teeth). The third isn't shown to the viewer, but starts a chain reaction of vomiting. A man in a cart then uses the vomit to make horchata^note  horchata is a Mexican rice, vanilla, and cinnamon drink that does have that dull brown vomit color, though sometimes, it's whitish brown.
• The time Stan and Francine kept giving Steve aging serum while he was asleep by violently jamming a large needle in him. One time they did it right into his temple, and it got stuck.
• Roger elbow-dropping a drug dealer and making his head explode. The shot turns it into Crossing the Line Twice by showing nearly twenty different action cuts from multiple angles.
• In "Don't Look a Smith Horse in the Mouth":
  • Roger tricks Stan into sexually pleasuring a horse, at which point the scene cuts to the protagonist washing his face in disgust.
  • A morbidly obese Mr. Tuttle crushes Snot.
• Stan transfers his consciousness into Klaus' decaying, zombie-like original body in "Da Flippity Flop".
• In "Kloger":
  • Klaus and Roger begin a secret relationship after having sex, which leads to a montage of them making out in various cringe-inducing ways.
  • Steve wants to get out of his school's fitness test, so he tries to catch Hayley's pink eye (which only worsens and gets more disgusting looking as the episode goes on). He ultimately succeeds in skipping the test by shitting his pants.
• The infamous scene from "Mural of the Story" where Stan attempts to make Hayley's face unrecognizable without proper experience in the procedure. It starts with Hayley's bloodshot left eye protruding from its socket, then the other eye pops out entirely, then he cuts her entire face off... The end result isn't any less unpleasant.
• "Stan & Francine & Connie & Ted" features the debut of Barry's parents, who convince Stan and Francine to join them at a nudist colony. Steve and Barry follow, because the former is worried the combination of his formerly promiscuous mother and sexually repressed father at such a place will lead to disaster. After he and Barry sneak in using a Totem Pole Trench, they lose the disguise, revealing themselves to be naked. Even in a cartoon, there is just something wrong with two naked 14 year olds on screen for one third of the episode, regardless of the censor blur. Even more so with them casually cavorting around with other stark naked adults. Worst of all, they have no need to be nude, they are just there to retrieve Stan and Francine.
• "Tapped Out" revolves around Francine secretly feeding Steve breast milk into his teen years, and comes to a head with Steve getting breast fed at a public showing of the play he is a part of, in front of the entire school and his family.
• In "Dressing Down", Hayley and Jeff start their own cruelty-free chicken farm. When they harvest the eggs from the chickens and attempt to make omelettes, they discover that all the eggs contain chicken fetuses (and somehow a snake fetus) instead of egg yolk. To prove to Francine that the whole thing wasn't a waste of time, Hayley and Jeff still use said fetuses to make omelettes, which look revolting. Hayley doesn't even manage one bite before puking.
• In "Into the Jingleverse", Francine mentions that Santa (one of the family's biggest arch enemies at this point in the series) once left a diaper full of shit underneath their Christmas tree.