Krusty Krab, the fictional fast-food restaurant in “SpongeBob SquarePants,” will never be real, but at least the second-best thing is — a Krabby Patty.

Wendy’s is releasing a special meal, in honor of the 25th anniversary of the “SpongeBob SquarePants” animated TV series, which includes a “Krabby Patty Kollab” cheeseburger and a “Pineapple Under the Sea” Frosty flavoring at its US and Canadian restaurants for a limited time beginning October 8.

The Krabby Patty is the same as a regular cheeseburger but with an additional slice of cheese and a “top-secret” Krabby Kollab sauce, the chain announced Wendnesday. The special Frosty is vanilla with a pineapple-and-mango-flavored puree swirled on top.

Tapping into consumers’ nostalgia by collaborating with a cartoon that millennials love could boost sales. Burger King also announced this week that it’s partnering with MGM’s “The Addams Family” animated film franchise for a “Wednesday’s Whopper” that has a purple-colored bun.

In a press release, Wendy’s said it only “makes sense that two of the most iconic squares in pop culture are teaming up,” a nod to the chain’s square burgers.

Using two foods that largely already exist on the menu makes it easy for employees to assemble the specials. McDonald’s often releases celebrity meals, which features food already on its menu but with a special name, finding financial success with them.

All fast-food chains are battling for dollars from American diners who are not going out to eat as often and spending less when they do, causing fast-food sales to slow and restaurant traffic to dip.

As a result, companies have released value meals and special promotions to ramp up sales. Whether the strategy is working will become clearer when earnings are released in the coming weeks.