Several female characters wear form-fitting outfits that accentuate their breasts and buttocks to an extent

Catwoman acts a little sensual around men, especially Batman

Barbara is briefly shown in a state of undress while putting on her costume.

Some characters kiss. One time, a kiss is forced upon a main character without their consent.

Some mild innuendos. The worst example is a female villainess makes sounds as if she's coming to climax during the literal climax of an episode in season 4.

Season 4 of the show is a lot more violent than the other seasons.

Frequent gun violence. One character is show to have been hit offscreen, but survives. Another character is hit with multiple rounds onscreen, but is revealed to be a robotic copy of a character.

Blood is shown, but it is rare and minor due to Fox Kids censors.

At least several uses of "god" throughout its entire run.

Drugs are mentioned a few times involving criminals, including dealing and drug addiction. Toxic gas is shown a few times to drug people in various ways.

Smoking hardly appears although the character of the Penguin is shown smoking a cigarette in a holder most of the time.

The episode "Mad Love" is fairly disturbing.

Harley Quinn is in an abusive relationship with the joker. He often yells at her and hits her, which may be frightening for younger viewers.

This show is darker than any other Batman television show, and certain characters like Two-Face, Man-Bat, Clay Face, Scarecrow, and Killer Croc are just some of several characters that are quite frightening.

Thematically, this show is extremely mature and down-to-earth, with subject matter involving loss, death and dying, and revenge which are very frequent in the series and can lead to various emotionally intense moments. But even more mature themes such as abusive relationships (in the episode "Mad Love"), as well as infertility (in the episode "House & Garden"), are touched upon as well.

Some episodes have a very depressing tone. The whole show has a very prominent dreary overtone to it.

The Scarecrow has some very disturbing episodes.