Animation in the ‘90s feels a bit like a fever-dream-- while Disney began a string of massively popular animated features, television introduced the world to some of the strangest, most oddball cartoon characters of all time, and recollecting them can often be a weird experience. Cartoon Network and Nickelodeon seemed to be duking it out over who could serve up the craziest concoction, with audiences across the world reaping the benefits. It was during this period that animators and writers wanted to take a more edgy approach to cartoons, sprinkling in risqué humor and adult themes that delighted parents and flew right over the heads of their children.

The decade was revolutionary for animation, jam-packed with screwy, off-the-wall characters that to this day remain beloved cartoon classics. From three superhero kindergartners to a conjoined cat and dog, to hipster beavers and a terrified but loyal pet who just can’t catch a break, the ‘90s were a wild and rowdy time for animation and cartoon lovers alike. These are the weirdest ‘90s cartoons we can’t seem to forget.

9 Aaahh!!! Real Monsters

From the creative minds behind the classic cartoon Rugrats, 1994’s Aaahh!! Real Monsters was developed by Klasky Csupo and follows a trio of young monsters: Ickis, a small red monster often mistaken for a rabbit; Oblina, a black and white, candy cane shaped creature and Krumm, a hairy orange monster with detached eyeballs. The three study the art of scaring humans in school, performing “scares” for class assignments. The character design for the monsters in the show partially drew inspiration from the 1968 film Yellow Submarine as well as taking elements of the film noir genre. USA Today praised the quirky show, calling it “garish and blissfully silly” and appreciating how its “outrageous characters have just enough Ren and Stimpy grodiness, but tempered with exceptional sweetness.” Aaahh!! Real Monsters ran for four seasons and featured 52 episodes before its conclusion in 1997. It seems to have even inspired Monsters, Inc.

8 Cow and Chicken

Cartoon Network’s zany animated comedy Cow and Chicken, from Fred Seibert's revered Frederator Studios, follows the surreal adventures of two talking siblings, Cow and Chicken. The delightfully strange show features an assortment of oddball characters like the duo’s flamboyant enemy Red Guy, a Devil like figure who constantly antagonizes Cow and Chicken. The series is famous for its grotesque and eccentric humor, like how Red Guy flashes his derrière to audiences, and how the characters all utilize sarcasm and slapstick antics. Creator David Feiss thought up with the idea of the show for his daughter, coming up with the story “on the fly” during her bedtime routine. Cow and Chicken had a few notable guest stars, such as Will Ferrell, Spongebob’s Tom Kenny, and Star Wars legend Mark Hamill. It ran for four seasons, from 1997 to 1999.

7 The Angry Beavers

Following the lives of beaver brothers Daggett and Norbert Beaver, 1997’s The Angry Beavers centers on the young pair as they move from their parents' house and become bachelors in the forest in the fictional Wayouttaatown, Oregon. Created by Mitch Schauer for Nickelodeon, the series was inspired by Schauer’s early years in Oklahoma in which he was homeless and often spotted beavers in a nearby river. He also was heavily against the beavers being soft and safe, instead opting for the duo to be bad-tempered and politically incorrect (it is called angry beavers, after all). Jazz and Spanish music feature prominently in the series, which utilized sounds in very specific ways. Schauer also cited The Flintstones, The Pink Panther and Rocky and Bullwinkle as primary influences for the show. Schauer and Nickelodeon often butted heads over restrictions and censorship, and after four seasons the creator and his crew devised the concept for the final episode: the beavers are informed via the mail that the show is canceled and are ultimately killed. Despite never being produced or aired, the finale’s meta concept helped The Angry Beavers go out with a legendary bang.

6 The Powerpuff Girls

What happens when you mix “sugar, spice and everything nice” and accidentally add a dash of “Chemical X?” You get three kindergarten-aged girls with superpowers, of course. Cartoon Network’s The Powerpuff Girls focuses on Blossom, Bubbles and Buttercup as they help protect the city of Townsville from wicked criminals and enemies. Created by Craig McCracken, the hit series debuted in 1998 and garnered rave reviews from critics and audiences alike with specific praise for its lowbrow humor and quirky characters. For the design of the butt-kicking trio, McCracken pulled inspiration from wrestlers and the paintings of Margaret Keane, drawing the three girls with large eyes, something which may have helped endear younger audiences to the massive incoming popularity of anime. The Powerpuff Girls introduced iconic villains, such as the mad scientist chimpanzee Mojo Jojo, the glamorous supernatural demon HIM and Bigfoot-hillbilly monster Fuzzy Lumpkins. The series ran for 6 seasons and spawned a feature film and TV specials. A live-action adaptation is currently in the works at the CW.

Related: Powerpuff Girls Reboot Loses Chloe Bennet

5 The Ren & Stimpy Show

Undeniably one of the raunchiest and dark-humored animated children’s shows of all time, Nickelodeon’s The Ren & Stimpy Show follows the adventures of the title characters: Ren, an emotionally unstable psychotic Chihuahua; and Stimpy, a dimwitted yet kind cat. John Kricfalusi created the kooky characters in 1978 for “personal amusement” while studying at college, with the aesthetics being inspired by Golden Age cartoons. The Ren & Stimpy Show was infamous for its adult humor, sexual innuendos and shock value, with the program’s staff not wanting to create an “educational” series. This stance bothered Nickelodeon and the show would probably never air on that channel today, but Ren & Stimpy would still go on to have a five-season run despite the deteriorating relationship between staff and network. The series had a long-lasting influence on animation in television and has since developed a faithful cult following.

4 Ed, Edd n Eddy

Detailing the absurd day-to-day life of three buddies with the same first name, Cartoon Network’s Ed, Edd n Eddy follows the trio on their numerous misadventures in their cul-de-sac. Danny Antonucci was dared to create a children’s cartoon while working on a commercial, so he conceptualized a show resembling classic cartoons from the 1940s-1970s. Antonucci is a strong advocate for hand-drawn animation and as a result, Ed, Edd n Eddy was the last major series to use traditional cel animation. The show was a smash hit for the network, with the trio garnering favorable comparisons to The Three Stooges. Ed, Edd n Eddy attracted an audience of 31 million households, was broadcast in 120 countries, and with a 10-year run is currently the longest-running Cartoon Network original series.

3 Rocko’s Modern Life

Depicting the surreal life of an anthropomorphic Australian immigrant wallaby named Rocko, Nickelodeon’s Rocko’s Modern Life was created by Joe Murray initially for an unpublished comic book series. The network gave the staff free rein and a lot of creative freedom with the show, resulting in the writers targeting both kids and adults. Rocko’s Modern Life was controversial for its adult humor, innuendos and satirical social commentary but entertained and amused the masses nonetheless; case in point, Rocko had a brief stint as a telephone operator, at what is implied to be a sex hotline during season one. It has been noted for its racy humor, with adults making up more than one-fifth of the show’s audience during its run, which is possibly one of the reasons that the Netflix movie 20 years later was so highly anticipated. The show ran for four seasons and at the time was the network’s highest-rated cartoon launch ever.

Related: Every 80s Movie That Turned Into a Saturday Morning Cartoon

2 Courage the Cowardly Dog

The beloved animated horror-comedy series Courage the Cowardly Dog follows the title dog who must overcome his own fears to heroically protect his edlerly couple owners from impending dangers and doom. The frightened Courage, loving Muriel, and grumpy Eustace are constantly being thrown into bizarre supernatural misadventures, with the tone of the show famous for its dark and eerie atmosphere and humor. Creator John R. Dilworth initially pitched the premise as a seven-minute animated short which would become the show’s de facto pilot; the short was nominated for the Academy Award for Best Animated Short Film in 1996. Courage the Cowardly Dog showcased the loyal pooch encountering aliens, monsters, mad scientists and demons, among a slew of other creepy villains. The show premiered at the tail end of the '90s, running from 1999 until 2002, earning praise by critics; PopMatters called it “a fascinating and textured mixture of cartoon and horror-movie conventions, and a joy to watch.” The terrified puppy got a chance to hang with another famously frightened dog, Scooby-Doo, in a fun recent crossover.

1 CatDog

Peter Hannan’s Nickelodeon creation CatDog depicts the life of the yellow conjoined brothers of two different species; one half being the refined and organized Cat and the other being the goofy and naive Dog. Performed by renowned voice actors Jim Cummings and Tom Kenny, CatDog gets into an entertaining array of misadventures and hijinks in their titular series. Hannan drew inspiration from the show after watching neighborhood cats and dogs fight each other, and felt it would be funny to see how they’d fare being joined together. With hilariously amusing supporting characters like Rancid Rabbit and a street gang called The Greaser Dogs, the show was not afraid to embrace being weird and eccentric. CatDog ran for four seasons, from 1998 to 2005 and remained a constant staple in syndication on Nickelodeon.