Incredibly sweet 'SpongeBob Squarepants' 20th anniversary special has a human Krusty Krab

Kelly Lawler
The voice actors behind SpongeBob, Squidward and more get on camera in adorable 20th anniversary special, "SpongeBob's Big Birthday Blowout."

SpongeBob is 20 years old, but he's still as sweet and naïve as ever.

Nickelodeon is celebrating the 20th anniversary of "SpongeBob Squarepants" with the delightful and adorable “SpongeBob’s Big Birthday Blowout,” an hourlong special airing Friday (7 EDT/PDT) that mixes the animated fun of Bikini Bottom with live-action appearances by the voice actors who have been behind SpongeBob, Squidward, Patrick, Mr. Krabs, Sandy and Plankton for all these years.

"Birthday" centers on SpongeBob's (Tom Kenny) birthday (although the age of the child-like sponge is kept cheekily secret), as Sandy (Carolyn Lawrence), Mr. Krabs (Clancy Brown), Patrick (Bill Fagerbakke), Squidward (Rodger Bumpass), Plankton (Mr. Lawrence) and the rest of the sponge's friends attempt to throw him a surprise party. Patrick is tasked with distracting his best friend, and the duo head on a tour of "Surface Land," where they run into David Hasselhoff (a longstanding "SpongeBob" tradition), scary "pie dragons" (dogs) and the "Trusty Slab," a burger joint with a greedy owner, a bored cashier and an over-eager fry cook. Sound familiar?

Just like many other anniversary specials, "Birthday" is full of celebrity cameos (look out for Tiffany Haddish and Sigourney Weaver) and tributes to the series' history and its creator Stephen Hillenburg, who died in 2018. There are throwbacks and in-jokes aplenty for longtime "SpongeBob" fans or even casual viewers who last watched it a decade ago (the iconic "my leg," of course, is featured).

But the sweetest part of the hour is the "Trusty Slab," where the voice actors appear onscreen as human versions of their Bikini Bottom characters, providing faces to the unbelievable work they've done for two decades. It's a short gimmick that may go over the heads of the youngest viewers, but it's touching for anyone in on the joke.

SpongeBob forever: Why, 20 years later, 'SpongeBob SquarePants' endures as one of the best kids' shows around

The special is further proof that "SpongeBob" has incredible longevity. The series feels just as smart and vital as it did when I was a kid. And as long as the actors stick around, it could go on for 20 more years.

This article originally appeared on USA TODAY: 'SpongeBob Squarepants' 20th anniversary special has human Krusty Krab