The Saturday Night Live star sasses it up on Fox’s new animated sitcom.

Actors don’t always know why they’ve been cast in certain roles, but Kenan Thompson is perfectly aware how he landed the part of acting principal Sue Sezno on Fox’s new high-school themed animated series Sit Down, Shut Up, which premieres this Sunday at 8:30pm after The Simpsons.  “I sassed it up a little bit,” the he reveals.  “The writers wanted a character that’s about to take over the school and people aren’t giving her the respect she needs.  I guess the lady that had the part before me didn’t sass it up enough, so I gave it a little attitude.”

As any SNL-addict knows, Thompson is that show’s go-to guy for chicks with attitude.  During his six-year stint on TV’s longest-running sketch-comedy series, he’s donned a wig and fake bra to play such sassy ladies as Virginiaca Hastings and Whoopi Goldberg.  “I’m just trying to be on TV,” he says modestly.  “Whatever they need me to do, I’m there to do it.”

To create his character for Sit Down, Shut Up, Thompson drew inspiration from some of the teachers he had during from his public school days in his native Atlanta.  “There was this one assistant vice president who later became the principal.  The way she carried herself made her seem a bit like a ghetto-type person, but she had through school and had her degree.”  Those memories helped him find the voice for Sue, who “takes no mess” even when she’s dealing with such disasters as a PTA-organized fundraiser gone wrong or students sabotaging a school fair.  In one clip, she orders a full body search for a kid that dares to smile at her after walking through the school’s metal detector.

Based on a popular Australian series, the American version of Sit Down, Shut Up is overseen by Arrested Development creator Mitch Hurwitz and features many of the stars of that cult sitcom, including Jason Bateman, Will Arnett and Henry Winkler, along with such past and present SNL players as Cheri Oteri and Will Forte.  “This is just full steam ahead comedy,” Thompson promises.  “Even if the characters confront a serious situation, it would be handled in a comedic way.  I want people to love this like they love The Simpsons or Family Guy.  It’s something new and different and super-funny.”

Check out Kenan Thompson’s official rules for being a great voiceover actor–and watch two promos for Sit Down, Shut Up–below.

Don’t stop at just one funny voice.
“Try to come up with as many different voices as possible.  That way, when you do land a job, you can show people the range you have.”

Leave your props at home.
“Props take away from your imagination.  When you’re doing voiceovers, it’s all in your mind.” 

Be open to improvisation
“I love to explore.  That’s the good part about comedy—you have to leave the window of exploration open.  You may think you have a funny premise, but as you explore, you’ll find yourself coming up with two or three new jokes.”

When possible, it’s always good to record with other actors
“When you record by yourself, it’s all on you.  When you’re with other actors, it’s more of a joint effort.  Also, it might save you some re-records because they won’t have to call you back in and say ‘Can you calm down this line?’”

Go for more than one take
“I like to do record each line a few different times, because you never know what they’re looking for until they’re happy.  You can always ask for one more, but it’s usually a consensus when you should move onto the next line.”