For John Kricfalusi, there was once a time when cartoons were really good.

Of course, as the creator of “Ren & Stimpy” – one of the most popular, subversive, gross-out cartoons in modern history – Kricfalusi has an entirely different idea of what “good” really is. And it’s far from wholesome and conventional.

“I grew up when they started ruining cartoons,” said Kricfalusi.

And he’s been on a mission to make cartoons better again ever since. Though Kricfalusi was once a pioneer in the genre of “adult” cartoons in a time filled with such kid-targeted programming as “The Smurfs” and other Saturday morning cartoons, his work has now inspired a growing trend of animators who create cartoons for a more mature audience.

The American Cinematheque is presenting an in-person tribute to Kricfalusi titled “What Makes a Cartoon Cartoony,” Sept. 7-8, where it will feature not only a retrospective of his work (including new episodes of “Ren & Stimpy,” set to air on SpikeTV in the fall), but also a look at some of the cartoons that inspired Kricfalusi, most of which were created in the 1930s-1950s – what he calls the golden age of cartoons.

“Ren & Stimpy,” which first aired on Nickelodeon in 1991, was the subject of many rave reviews and even a little controversy when the network refused to air one of Kricfalusi’s episodes titled “Man’s Best Friend,” which featured a scene where one of the characters is violently beaten to a pulp. Kricfalusi maintains that while he’s not a fan of blood and gore. Violence used as slapstick is something that’s been used in entertainment since the early days of “The Three Stooges.”

“I like weird cartoons,” said Kricfalusi. “That’s the whole point of cartoons because you can do whatever you want, and as an animator I think you should take advantage of that ability.”

Kricfalusi says one of the reasons for his success as an animator has been his willingness to push the envelope in terms of what he was able to create with just a pencil and paper.

“It’s like if you went to a magic act; you’d expect the magician to perform the impossible, like pull a rabbit out of his hat or make something disappear,” said Kricfalusi.

Today, animators are finding more and more that the key to success is engaging more than just children with their cartoons. With such popular cartoons as “South Park” and Cartoon Network’s “Adult Swim” (a nightly programming of “mature” cartoons such as “Aqua Teen Hunger Force,” “Sea Lab 2010” and “Family Guy”), it’s hard to say cartoons are just for kids anymore. Second-year international development studies student Rafi Crohn says he learned this living in the dorms last year first hand.

“‘Adult Swim’ was really popular; it was a cool thing to watch among a lot of my friends,” said Crohn. “As far as cartoons being kids’ stuff, I think it’s possible that younger audiences do respond to the fantastical aspect of them, but that doesn’t mean adults can’t, either.”

For many students in the UCLA animation department, though, appealing to a wider audience is more difficult than simply making a decision to create more mature material.

“In this country, any time people see cartoons, they expect them to be humorous,” said graduate animation student Rob Fendler. “That leads to a lot of the same variety in what you see in television and on the big screen and really pigeonholes the entire genre.”

Still, Kricfalusi says it is his goal not to limit the range of those who watch his cartoons with more mature plot lines and added violence but instead make it accessible for all ages, even adults.

“The fact is, kids love it, too,” said Kricfalusi. “Kids love being terrified. I remember when I was a kid, and I loved that sort of stuff. Maybe you can feel the violence a little more (in my work), but I think that’s just part of what makes it real.”