Romance and puberty are frequently featured themes and are the main plot points of several episodes.

A boy gives a merman CPR, but it is very clearly made to look like they're actually kissing.

One of the oddities in the Mystery Shack is called the "Sascrotch".

A man is married to a woodpecker, claiming that it's still "totally legal".

In an episode, Dipper accidentally lays on his crush, Wendy's, bra. She mentions, "Dude, you're laying on my bra." Dipper then screams in embarrassment.

Very frequent mentions of boyfriends and girlfriends, kissing, crushes and Mabel is 100% boy crazy throughout the whole series.

One of the main protagonists has a hopeless crush on someone much older than him. This is mentioned frequently throughout the series, and is often portrayed in a vaguely suggestive way.

One character is frequently seen wearing only boxers and an undershirt throughout, in a nonsexual context. Additionally, some characters are occasionally seen shirtless, in swimsuits or in their underwear, again, in a nonsexual context.

Puberty is mentioned throughout. In several episodes, one of the main protagonists is insecure about his masculinity deals with issues such as chest hair, voice changes, sweating issues, feeling awkward, etc.

Some characters have books or magazines with sexual content; this includes characters reading "age-inappropriate" romance novels, a book about puberty ("Carpet Diem"), adult magazines ("Scary-oke"), etc. There is no explicit sexual content in any of these instances and it is presented in a comedic manner.

There are some mild sexual jokes, including one about somebody's Internet history being creepy ("Into The Bunker"), and a brief scene of somebody taking a bath with squirrels ("Gideon Rises") etc.

One of the main protagonists (who is 12) flirts with and has brief relationships with a variety of boys, many of whom are her her age or slightly older than her, one of whom she shares a kiss with ("The Deep End").

A reference to testosterone.

A few very minor characters die or are implied to have died in various episodes. Deaths are usually off-screen, but when they are on-screen, it's never a graphic or bloody death and is often presented in a comedic manner.

Moderate nose or mouth bleeding can be seen in some episodes.

The pages in Journal 3 about Bill Cipher have red blood splattered on them.

Bill cipher disfigures a human face in one scene with his powers.

Self-harm.

Action and fighting is present throughout the show. Some cartoon violence, brief injuries, and red cuts and bruises are shown, but there is usually very little blood or gore.

Characters are occasionally eaten whole, but later turn out to be fine. ("Summerween"; "Land Before Swine")

Monsters are sometimes dismembered, crushed, beaten, etc., but do not have any red blood or gore. Any monster blood is usually green. ("Scary-oke"; "Into The Bunker")

Occasionally, characters can be briefly seen without skin, revealing the flesh, muscles, and bones beneath. ("Sock Opera"; "The Inconveniencing")

There is some red blood, but this is usually shown briefly. In "Northwest Mansion Mystery", blood oozes out of the mouths and eyes of animal heads on the wall, and in "Society of the Blind Eye", through the bandages of a character's injured hand. A character gets a nosebleed in the climax of "Gideon rises", In "The Last Mabelcorn", a character is very briefly shown donating their blood.

In "Northwest Mansion Mystery", a character is killed after being hit on the head with an ax (off-screen).

No cursing but other Insults like: "suckers", "dumb", "idiots", "stupid", "shut up" etc.

Occasionally, there is discussion of murder or death. Very rarely characters verbally threaten to kill one another.

There is an instance of symbol swearing in the episode "Society of the Blind Eye".

There are some jokes about swearing, but no actual swearing.

Some minor things were censored and removed from the series on Disney+.

A witch removes Grunkle Stan's hands. He angrily requests that she return them to him so he can "share a special gesture" with her, implying that he's going to give the middle finger.

A man tells a boy to "go suck a lemon".

Juvenile insults like: "poop head", "butt face", "jerk", "nerd", "dork" etc.

Some religious exclamations.

Instances of "heck."

It is implied that characters make inappropriate hand gestures. ("Society of the Blind Eye"; "The Golf War")

One incomplete use of "son of a..." ("Not What He Seems")

The expletive "flipping" is used once.

At least 2 uses of oh my god in the pilot.

A character asks for a glass of a restaurant's most expired apple cider.

Overall, alcohol, drugs, and smoking are very infrequently mentioned, and mentioned in a comedic manner when they are.

Two underage characters enter a bar with fake IDs ("Headhunters"). This scene is meant to be comedic.

Characters engage in an exchange of fairy dust and butterflies, but the set-up mirrors a drug deal. ("The Last Mabelcorn")

There is only one instance of smoking, where a character is seen with a pipe in his mouth. ("Headhunters")

Fairy dust is strongly implied to be an illegal knockout drug and is used to sedate a unicorn in "The Last Mabelcorn". In the same episode, a satyr is knocked out with chloroform. Both these scenes are brief and played for laughs.

In "The Golf War" Mabel drinks orange juice and says she "needs something to take her mind off this"

Suicide pills are used once.

In another comedic scene, a character experiences fantastical hallucinations after consuming outlawed candy. ("The Inconveniencing")

The character of Bill Cipher does some disturbing things, such as pulling teeth out of a deer's mouth ("Dreamscapers"), summoning a constantly screaming severed head and then stripping all the flesh from it to reveal a skull ("Sock Opera"), rearranging Mr. Northwest's facial features entirely ("Weirdmageddon Part 1"), or speaking in a demonic voice (various episodes). These moments are very brief, but may scare some younger or sensitive viewers.

Characters frequently use black magic to solve problems or for their own personal gain. This includes multiple instances of chanting incantations, spells, curses, magic crystals, potions, summoning rituals, demonic possession, raising the dead, etc. Some sensitive viewers may find these things disturbing.

Some spooky visual scenery throughout, such as dark caves and foggy lakes.

Non graphic severed body parts are infrequently shown. During Bill's Weirdmageddon, a giant severed head with an arm on top chases Dipper and says it wants to eat him. In another episode, a witch who collects severed hands, steals Stan's hands.

Season two can get Moderately to severely intense and disturbing.

The ending is very sad.

It's worth mentioning that some of the official merchandise for the series such as the real life Journal 3 have slightly edgier content than the tv series. Another real life book called "The Book of Bill" which explains Bill Cipher's origin story is specifically written for adults and contains a content warning on the cover because of this.

Bill cipher looks innocent but he is actually a demon.

There is horror comedy.

For elementary schoolers/kids and up.

Only intense if youre 11 or younger.

Mystery and horror are frequently featured throughout the show. Although the horror can be considered relatively mild, many episodes have a lot of suspense.

Dipper and Mabel encounter a variety of intimidating creatures such as ghosts, demons, zombies, shapeshifters, and various kinds of monsters. Some of these may be frightening to young children.

There are some scenes meant to shock viewers, such as a scene where blood suddenly oozes out of an animal's eyes and mouths ("Northwest Mansion Mystery"), a scene where the bodily openings of Mr. Northwest's face are rearranged ("Weirdmaggedon Part 1"), etc. This contributes to the horror element of the show.