LOS ANGELES — Nickelodeon will make a “SpongeBob SquarePants” spinoff for Netflix as part of a multiyear content-production deal that reflects the pressure on Netflix to fortify itself against new streaming competition, notably Disney Plus.

Netflix and Nickelodeon announced a deal on Wednesday for Nickelodeon to create and produce original animated feature films and television series based on Nickelodeon’s library of characters. Shows based on completely new characters are also part of the agreement. The companies gave no specifics on characters, the number of shows or how many years.

But the partnership involves a music-based project centered on Squidward, the malcontent anthropomorphic octopus on “SpongeBob SquarePants,” according to two people briefed on the matter , who spoke on the condition of anonymity to discuss still private details. The people said the overall deal was worth more than $200 million to Nickelodeon.

Disney Plus, Disney’s streaming service, became available on Tuesday. In a statement on Wednesday, Disney said 10 million people had signed up for the service, surpassing analyst expectations.