Sirena Irwin Reflects On 25 Years Of Iconic 'SpongeBob' Voices And The Characters That Made Bikini Bottom Unforgettable

In high school, I couldn't walk down the hallways without people shouting, "WHAT!? What are they selling?" "THEY'RE SELLING CHOCOLATE!"

Mary from SpongeBob SquarePants is talking to a shriveled figure sitting in a green chair

Sirena Irwin has brought dozens of fan-favorite SpongeBob characters to life for over 25 years. Her resume includes 'lazy' Mary, forced to take care of her chocolate-hating mother, the real estate agent driven away by SpongeBob, the ever-so-sassy magic conch shell, Mrs. Krabs, Mrs. SquarePants, and more.Leading up to SpongeBob's Halloween-themed 25th-anniversary special “Kreepaway Kamp,” I sat down with Sirena to learn about voicing some fan-favorite background characters.

A woman with light hair styled in an updo is seen smiling at the camera. She is wearing a black jacket over a blue top
Sirena Irwin / Via Provided by Sirena Irwin

1) Sirena originally auditioned for the roles of Sandy, Mrs. Puff, and Pearl.Sirena Irwin: SpongeBob was the first project I booked after coming to Los Angeles. I had just finished college, and a friend said, "Hey, I know this guy who just got a show picked up at a network called Nickelodeon, and you should submit your reel!" I found out this guy's name was Steve Hillenburg. I sent him my reel, literally through the USPS, because there was no internet then.I was called in to read for Sandy, Pearl, and Mrs. Puff. I heard back that they were not casting me as any of those characters, but they liked that I had range and wanted to include me as a utility player. They explained I'd be recurring as SpongeBob's mom, but they didn't intend to have his parents in there a lot because they didn't really want parental figures around.Then we were off and running, filling in other voices as well. "Opposite Day" was one of my first episodes. I got to play the real estate agent, which was super fun! I guess it was good enough for me to come back and try other characters.

"He's Squidward, he's Squidward, you're Squidward...I'm Squidward!"

SpongeBob SquarePants, Patrick Star, and Squidward Tentacles are confronted by an angry fish wearing a magenta suit inside

2) The writers send over the storyboards and script at least a day before recording lines.It gave me the opportunity to see what the writers and artists had imagined for the character. I could start playing with voices based on who this character is, what part they serve in the story, and how they look. Have they drawn them straightforward? Is it an old lady? There's all this variation from the incredible minds and brilliant artists that have worked on the show throughout the years. We get to just spark off that, which is so much fun.Luckily, when doing utility work, if there’s a voice that comes back in an episode months or years later, the engineers provide a reference of what I previously did for the character. So I hear it and can get right into it, and that's very helpful.

"Hey, there's no ice!"

Officer Nancy, a character from SpongeBob SquarePants, holds a red straw and a drink can, appearing to be inspecting something seriously

3) Sirena draws inspiration from voices she hears in everyday life.I've been playing a recurring character called Lady Upturn. I just think she's so pompous and wonderful. The week before I got her first script, I had been doing something at city hall in town, and I heard a woman say something like, "Look at them twirl!" [imitates Lady Upturn's voice]. And I was thinking, I love that voice so much!When I hear a voice I love, I kind of try and stay near that person. I probably seem super cringy. If I'm at a cafe or wherever, I'll get in line and just listen to how they're talking, where they're putting the sounds, how they're enunciating, or if it's an accent. I’m listening to the details of it. And this one just captivated my interest. When I got the script and the board, I thought this could be a fun voice for her character.

Lady Upturn stands with a purse and leash in front of the Krusty Krab, a restaurant from the animated show SpongeBob SquarePants

4) In the beginning, the voices of the background characters were not meant to be unique.In the first maybe half-decade or so, Steve [Hillenburg] wanted the incidentals [background characters] to have grounded, normal voices. He felt that with Spongebob, Squidward, and Patrick, there was already so much going on that he was looking for the world around them to feel grounded in something real.

"So now the talking cheese is gonna preach to us!"

Patrick Star stands with other animated fish characters, including an angry fish with a headscarf and yellow blouse, from the show SpongeBob SquarePants

So with Lady Upturn, I didn't know if they would go for the voice I had in mind. And I brought it in. I'm like, "Hey, how about this?" And they said, "Yeah, let's do it!" And it's just been fun. Every time I get a script with her, I love it.

5) Some of Sirena's favorite roles include the magic conch from "Club SpongeBob" and Mary from "Chocolate With Nuts."The one that surprises me the most is the magic conch because I love that episode so much. The magic conch is such a simple part of it, but it was super fun to do originally. I think it was my nephews who were like, "Do you know how popular the magic conch is?" I didn't know. And they sort of showed me it was actually a thing that people enjoyed."[imitates magic conch] Try asking again."

"Can I have something to eat?" "No."

Squidward from SpongeBob SquarePants holding a purple magic conch shell in an underwater setting with seaweed in the background

"Chocolate With Nuts" was recorded pre-pandemic, and we were all in the booth together. Now, we are mostly in the booth, and we've kind of come through the other side. I love group recordings, which don't always happen these days in animation just because of people's hectic schedules. It was just a playful experience. We got to find those characters together, the mother and the daughter, and the sort of 'put upon feeling of having to care for your mother.'And I love Tom's [Kenny] voice so much for Mary's mom. Recently I saw him and said, "Wait, let me hear that voice again!" It's so good! The writers created this great relationship between these two. I wish they were in more episodes!

SpongeBob SquarePants, Patrick Star, and an elderly character in a wheelchair sit around a table with drinks in a dark, luxurious room

6) On voicing Mrs. SquarePants and Mrs. Krabs:I got to work with Tom, who plays Mr. SquarePants. I thought of Mrs. SquarePants as very 'apple pie', almost in the range of [I Love] Lucy without the quirkiness. The pearls she wore also brought me there.

SpongeBob SquarePants, and his parents stand behind a cake with "Thank You Mrs. Puff" written on it, smiling and looking happy

For Mrs. Krabs, I always think of a pirate, an old pirate, and then I try to make it an old lady. I feel like she continues to evolve, but she's got this undying love for her son, like [Mr. Krabs] can do no wrong. There was a scene with Mrs. Krabs' muscles that totally brought me back to my childhood.

"The formula? Is that what this whole thing was about?"

Mrs. Krabs flexing her muscles in a scene from SpongeBob SquarePants, wearing a purple outfit and looking determined

When I was a kid, I used to bring people over to my house to look at my mom's muscles. She plays harpsichord, an early music keyboard, and she was such a badass. With being a harpsichordist you end up having to carry your own harpsichord. You have to do all your loading in and out of gigs, and I distinctly remember being so impressed with my mom's muscles that I needed everybody to see them.7) Sirena often stays to watch the cast record, even if she is done with her lines.Generally, we are booked for four hours to do a session, and I might have three to five lines. Sometimes, they'll record my lines first, so I'm free to go, but I won't go. I love watching this particular group at work. I learned so much from everything, especially since I came in as a complete newbie.These people on this show continue to teach me and inspire me. And, you know, they get my endorphins going. I'm so privileged to be in that room. I always tell Tom [Kenny], "You don't have to knock my lines out. I'm fine to stay here. You don't have to get me out." I'm staying anyway because there's too much good stuff going on to miss any of it.

"He's playing with a reef blower!"

Squidward is pulled back by another Squidward, while a third Squidward walks away holding a clarinet in this "SpongeBob SquarePants" scene

8) The cast gets opportunities to improv lines during the recording process.At some point, whoever was directing would break up the script into scenes. We would first do a couple of passes through as written. We all started improvising, and I believe it was Steve directing at the time. He was like, "Okay, listen, I really want to get the script as written. So why don't we do two passes as written, and then on the third pass, if you have an idea that's burning, go for it."That was the great thing about recording together as an ensemble. If somebody went for something, then we could also play with that idea, and we're all there to do it. I'm not sure how much of that they actually used or how much of that was just to appease us. But we felt like we had a contribution of sorts, and it was nice that was allowed.

"No one advances past me, Lipp Cervas!"

Animated character Lipp Cervas from the TV show "SpongeBob SquarePants" is standing in a heroic stance with a wide, exaggerated grin

9) Mr. Lawrence (the voice of Plankton/Larry the Lobster) signed a picture for her mother as a surprise.There was this one episode ["A Life In A Day"] with Larry the Lobster, voiced by Mr. Lawrence, and I just remember the repetition of "living like Larry." It just caught on. I was visiting my mom, and I was telling her about "living like Larry," and then she got to saying it. Ultimately, I got a little picture of Larry pumping iron and got it signed for my mom. It's one of those cute things that just sort of spun off.

"Livin' like Larry!"

Larry the Lobster, a buff lobster character from SpongeBob SquarePants, flexes his muscles while holding a blue dumbbell. A surprised fish stands nearby

10) On 25 years of SpongeBob:Every episode is incredible to me because I'm learning something—everything from the artists to the writers to the engineers to the actors. I see it as a gift. The whole cast and crew have been so supportive over the years. I came to Los Angeles on my own, and they were the first group of people that had come together where I felt a sense of family. I always felt like they were looking out for me.Steve Hillenburg knew that I was also a writer, making films and doing all these things. Every time that I came into session, he'd be like, "Well, what are you doing? What else is going on?" He really was supportive and encouraging in a meaningful way. I'm so grateful for the gift this show continues to give and the experiences that I continue to have.I have this idea that I've wanted to pitch to Nickelodeon, where I go around the globe, meeting the other utility actors in various countries who voiced the same characters that I've voiced on SpongeBob. What are they doing now? In addition to doing utility voices like me—did they also do the voices of Sandy, Mrs. Puff, and other main characters? I just think it would be such a cool way for kids to get a sense of the world community. I love the fact that this show has supported so many actors over the years. And I cannot say enough how grateful I am for it!I remember when we had done ten years, and we were doing a table read. Tom mentioned how lucky we are that we've been able to be on this show for ten years and how rare it is in this industry. Here we are at twenty-five now, and it's kind of mind-blowing. I can't even believe it. Do you know what this means? I'm old!

Group of animated characters from SpongeBob SquarePants, including Mrs. Puff, Pearl Krabs, and Mary, in a crowded and whimsical scene

Thank you to Sirena for such an interesting conversation (and for doing all the voices while we chatted)! In addition to voice acting, Sirena now works as a voice director, credited on hundreds of television episodes. To learn more about her career, check out her website. You can also find more about Sirena's work on her Instagram (@sirenairwin) and IMDB page.Keep an eye out for new SpongeBob! “Kreepaway Kamp,” a Halloween-themed special, airs on Nickelodeon and Paramount Plus on October 10th.

SpongeBob SquarePants and Patrick Star in a poster for the SpongeBob SquarePants Kreepaway Kamp Halloween special, premiering on Nickelodeon and Paramount+ on October 10
Nickelodeon Animation Studios, United Plankton Pictures / Via Nickelodeon Animation Studios